The field of synthetic biology has exploded over the past decade, having a major influence on fields such as metabolic engineering, protein engineering, digital biology, and whole-genome engineering.

Biosensors & Biochips Technologies: Contribution to the Future Sustainable Life

The field of synthetic biology has exploded over the past decade, having a major influence on fields such as metabolic engineering, protein engineering, digital biology, and whole-genome engineering. In the framework of iterative “design-build-test” development cycles, a significant portion of synthetic biology innovation has taken place. In the field of synthetic biology, progress can be associated with innovations in each of the processes of “design”, “build” and “test”. For example, there has been a major push to standardize elements within synthetic biology, with significant attention being paid to modularity and “plug and play” components. This modularization, along with the accelerated progress in systems biology, has allowed the “design” stage to become less time-consuming and less reliant on advanced knowledge. In recent years, the cost of DNA sequencing and synthesis has also decreased dramatically, allowing large constructs to be synthesized cheaply. In the ‘build’ phase, this has facilitated a rapid improvement, helping researchers to investigate a larger percentage of the space of the biological solution. Finally, within the synthetic biology “test” phase, high-throughput screening has also become a focal point. The increased “design” and “build” potential has contributed to an increased demand for success in the assessment of the plethora of new designs. In turn, this was done by incorporating robots and high-throughput analytics into the laboratory setting, in which new models can be evaluated to a level that is not achievable for human researchers.

Biosensors represent a groundbreaking emerging technology for high-throughput screening that can be implemented. Most precisely, they are classified as an analytical tool consisting of biological components used to detect and generate a signal for the presence of a target ligand. Synthetic biology is at the forefront of biosensors, both as a tool for high-throughput screening, but also as the direct result of developments within the field of synthetic biology itself. In addition, because of the unparalleled specificity and sensitivity that biological parts provide relative to conventional analytical methods, biosensors have gained expanded interest as alternatives to traditional analytics.

The design and construction of biosensors is a multidisciplinary endeavour and can include expertise in areas such as protein engineering, molecular biology, affinity chemistry, molecular dynamics of nucleic acid, materials sciences, and nanotechnology. Biosensors interface with a target ligand at their most simple stage, undergo some type of modification, and output a signal. There is a great variety of potential configurations in all the parts of this process. Target ligands range from single atoms such as calcium, to entire proteins such as thrombin, all the way through. Processes as varied as enzymatic activity, fluorescence, electrical current generation, and transcriptional activity include output signals. The mechanisms that transduce ligand recognition into functional signals are just as diverse.

In the field of analytics, biosensors represent a significant step forward. In order to move analytics away from purely physics- or chemistry-based frameworks, the integration of biological components in sensory diagnostics has begun. This has allowed analytical functions that are not well adapted to conventional methods to conduct a vast diversity and specificity of biological components. The theoretical and demonstrated biosensor applications cover a significant range of human society and activity. Biosensor applications are grouped into three broad categories, depending on their measurement scale.

• Group Diagnostics: Environmental, Agricultural, and Industrial Applications
• Point-of-Use Diagnostics: Medical, and Security Applications
• Single-Cell Diagnostics: Metabolic Engineering, and Synthetic Biology Applications

The current food production faces immense challenges from the increasing human population, the maintenance of clean resources and food quality, and the protection of the environment and climate. Food sustainability is mainly a cooperative effort that results in the development of technology funded by both governments and companies. Several attempts have been supported to overcome challenges and improve the drivers in food production. Via their applications, biosensors and biosensing technologies are widely used to solve the major challenges of food production and its sustainability. As a result, there is a rising need for biosensing technology in the area of food sustainability. A technological system combining several technologies is defined by microfluidics. Nanomaterials, with its biosensing technology, is known to be the most innovative tool strongly associated with world populations in dealing with health, energy, and environmental issues. The need for point of care (POC) technology in this area focuses on analytical tools that are fast, simple, precise, compact, and low-cost.

For our existence and lives, food with its production industry is essential; and its sustainability is essential in continuous human growth on the planet. Current food production is facing immense difficulties from increasing human population, maintaining clean resources and food quality, and protecting environment and climate. Some of these issues stem from food production itself; others stem from other food production-related industries. Food recalls, for example, trigger major damage to food brands’ credibility and prestige, with an estimate of $15 million per incident over the last few years. 48 million sick cases are responsible for 3000 fatalities annually due to foodborne illnesses.

Food safety is largely a cooperative effort arising from both governments and companies in technology development. In order to pose new challenges in food safety issues, information technologies such as blockchain technology can accelerate communication between food quality, media and consumers. Five challenges can be summarized as the main challenges in the sustainability of food production: the production challenge of food safety and security; the quality challenge of food diversity and quality; the economic challenge in the leading food system, including its packaging and supply chain; the environmental challenge, including the processing of food waste; and the engineering challenge in the creation and generation of novel food.

Basically, a biosensor is an analytical instrument used to measure a sample’s molecule of interest (target). In general, a bio-recognition factor (aptamer, antibody, enzyme, etc.) that is unique to the target is used. A physiochemical or biological signal is elicited by molecular recognition events between the recognition element and the target compound, which is transformed into a measurable quantity by the transducer. Signals are shown in either optical (colorimetric, fluorescence, chemiluminescence and plasmon surface resonance) or electrical (voltammetry, impedance and capacitance) or any other chosen format (Figure 3).

Figure 3. Classification of biosensors based on transducer and bio-recognition elements used in food analysis

As one of the primary objectives of food analysis, food safety is a major health issue in both animal and human lives. The advancement of food safety analytical technology means that it thrives in line with the rising interest in and emphasis on food supply safety issues. In food safety analysis, traditional approaches are labour-intensive, time-consuming, and need trained technicians. The application of microfluidics in food safety analysis provides fresh insight about how to detect foodborne toxins, allergens, pathogens, hazardous substances, heavy metals, and other contaminants effectively and rapidly. Microfluidics’ features, such as it miniaturize-capability, compact and reducible quantities of samples and reagents, make it a perfect technology for the development of food sustainability. Complex food matrix preparation and difficult manufacturing steps are the current challenges in the application of microfluidics to food sustainability. These challenges can be addressed by leveraging physical properties dependent on specific test targets, designing complex real food analysis microfluidic platforms, and incorporating into microfluidic systems biomolecules such as food proteins and DNA.

Nanomaterials in biosensing technology

With its biosensing technology, nanomaterials are the most promising tool in dealing with health, energy and environmental problems associated with population in the world. Particles smaller than 100 nm in at least one size dimension are known as nanomaterials. These nanomaterials are biocomposite polymers based on metal, metal oxide and carbon, and different types of nanoparticles have been established, such as magnetic iron, aluminum, gold, silver, copper, silica, zinc, zinc oxide, cerium oxide and titanium dioxide nanoparticles, and single/multiple walled carbon nanotubes (CNTs). Nanotechnology and its agricultural development have been greatly extended in different fields. These fields include food production, crop protection, detection of pathogens and toxins, purification of water, food packaging, disposal of wastewater, and environmental remediation. Improving the productivity and performance of applications is the priority of these agricultural fields.

In the field of food safety and protection, biosensing technologies have been developed for nutrient and quality detection, detection of pathogens and detection of toxins, as listed below.

Nutrient and quality detection

Food protection measures can be split down into two categories: post-harvest loss and food biosecurity. Food biosecurity means food contamination and degradation, which is addressed in the later sections, by environmental, political, unfair economic gain, warfare, or exacting revenge. Post-harvest loss, on the other hand, suggests the nutrients and edible conditions in food that need to be maintained between the harvest period and the moment of consumption by technologies. Since time differs from minutes to years, in maintaining and reducing losses, technologies focusing on reducing post-harvest losses are important.

To maintain food quality and to avoid post-harvest losses, new technology such as biosensing can be used. Biosensors have been developed, for example, to detect and analyse quantities of sweeteners in foods that can be used to detect both natural and artificial sweeteners. Sweeteners are widely used in food production and processing, but they have recently been identified in humans as causing health problems. A multi-channel biosensor has been developed to use electro-physiological sensing from taste epithelia to detect and analyse both natural and artificial sweeteners. To detect long-term signals from sucrose, glucose, cyclamate, and saccharin, respectively, the signals are studied through spatiotemporal techniques. The biosensor can distinguish between different concentrations with dose-dependent increased responses of the taste epithelium from different sweeteners. It can also distinguish between two natural sweeteners: sucrose and glucose, with two signal patterns. For glucose, the detection range is 50-150 mM, and for saccharin, 5-15 mM.

Detection of pathogens

Due to their reduced format, biosensors targeting pathogen detection such as bacteria (Table 1) and fungi (Table 2) started more than two decades ago; one device to address multiple problems, and a multi-panel signal detection. The ligand motif is a crucial element in the biosensor design for pathogen detection since it determines the sensitivity and efficiency of the device. The aim is to establish a fast, specific, and sensitive platform to detect in food samples the presence or absence of pathogens. It has been discovered that there is no ideal ligand, and various ligands have different advantages. The combination of bioreceptors to detect a large variety of microbes in different samples poses current challenges in pathogen biosensor detection; new synthetic ligand designs such as aptamers, small molecules, and peptides; and the incorporation of different ligands into a portable device to achieve rapid, effective, and low-cost detection.

Detection of toxins

The mainstream of development in food safety is electrochemical biosensors for rapid detection and assessment of food toxins. Numerous platforms have been developed to allow customized and individualized devices to meet particular environmental and organizational requirements and to reach the nM to fM detection limit levels. For example, to encourage unique binding profiles, bioreceptor arrays address individual electrodes functionalized with different bioreceptors with binding targets. In addition to electrochemical biosensing, toxin and chemical detection in food production have been applied to other biosensors such as optic and piezoelectric sensing (Figure 4). In order to sense toxins, fluorescent nanoparticles have been produced in foods and bodies, including on-surface, inter- and intra-cellular foods.

Figure 4. Predominant food contaminants and the target analytes in the food manufacturing industries

Toxin extraction from complicated food samples is one of the main obstacles in creating a fully automated toxin detector. To automatically assess their harmful levels from food and water samples, potential systems are expected to extract, process, and measure toxins. In identifying, discriminating, and quantifying chemical toxins in food matrices, sophisticated separation strategies have been coupled with SERS. In addition, even though they are typically in lower amounts, chemical contaminants from food processing can be a challenge. Lower stability, selectivity and sensitivity are another challenge in food toxin detection, where MIPs can be a solution to provide stable and low-cost alternatives.

Heavy metals like Ag⁺, As³⁺, Cd²⁺, Hg²⁺, Pb²⁺, and Zn²⁺ are known as chemical pollutants that form stable states of oxidation and interfere with metabolic pathways, resulting in health problems. Aptamer and DNA-based biosensors can detect heavy metals at both nanoscale and very large-scale levels, which are appropriate for food safety screening and monitoring. In order to detect arsenate in food, a heavy metal detecting biosensor is based on genetically modified bacterial cells and a green, fluorescent signal amplifier. With a detection range of 5-140 μg/L of arsenic, its arsenic detection lasts just one hour and can be integrated with optical power output for its future biosensing optical fibre. Other biosensing technologies like aptamers, nanoparticles and graphene electrodes have been successfully applied to the identification and evaluation of arsenic, with the potential to be produced as fast, simple, easy-to-use, and low-cost devices.

Nanotechnology has been adapted to two separate fields of agri-food pesticides: as a pesticide delivery vector for pesticide management and as a trace-amount detector for pesticides. In the first field, nanoparticles are able to slowly modify pesticides to target insect pests, which helps prevent groundwater and topsoil pollution, reduce pesticide levels and improve efficiency. In the second field, bio- or biomimetic-based nanotechnology, like antibodies, enzymes, aptamers, and MIP-like macromolecules, improves stability, selectivity, sensitivity, and speed of detection. Furthermore, bacterial, fungal, algal, and mammalian cells are all cell-based biosensors used in pesticide and herbicide detection, helping to establish fast, reliable, real-time, and cost-effective tools for decontamination procedures and preventive casualty damage.

Carcinogens, odorants, and marine contaminants are other toxins that are significant in food production. Carcinogens are a complex group of trace amount of toxins, like pesticides, heavy metals, mycotoxins, and acrylamide, in which the difficulty of identifying trace-amounts is a challenge; and imprinted aptamers, nanotechnology, and biosensing are optimistic for promising future use. Sensitive and soluble molecules effective in odour detection for olfactory animal systems are odorant binding proteins. A nanosensor combining localized SPR and small odorant binding proteins from honeybees has been established in which the detection range is 10 nM – 1 mM using a quantitative array of nanocups. To monitor and preserve a stable environment for marine food systems, marine contaminant detection is used. Finally, through their sensitive detection capabilities, miniaturized devices, wireless communication, and small-scale networks, biosensors can be applied to marine food safety to be established as advanced analytical and monitoring tools.

Another development kit for food safety biosensors focuses on the detection of genetically modified organisms (GMOs) in food products. Since the 1990s, GMOs in all fields of agricultural products have been considered a biotechnology revolution. To present, more than 45 percent of the world’s soybeans, 40 percent of corn, and 50 percent of cotton are GM products; and GM is also used in livestock. Recent research, however, indicates that GMO products can affect human and animal bodies through gastrointestinal problems, antibiotic resistance, allergenicity, diversity of farm products degradation, and undesired gene flow to other species. Biosensors are designed to measure GMOs in foods and feeds using isothermal DNA amplification and fast detection signal detection to identify GM genes. Detecting unidentified DNA genes that can be resolved by high-throughput technology like the combination of biosensing and arrays, and the development of databases of GMO genes are the key challenges in GMO detection.

Biosensors & Biochips for environmental monitoring

Due to the strong connection between environmental pollution and human health/ socioeconomic progress, environmental monitoring has become one of the priorities on a European and global scale. Biosensors have been commonly used as cost-effective, rapid, in situ, and real-time analytical techniques in this field. The recent development of biosensors with new transduction materials obtained from nanotechnology and for multiplexed pollutant detection, involving multidisciplinary experts, explains the need for compact, fast, and smart biosensing devices. Several recent developments exist in the monitoring of air, water, and soil contaminants by biosensors under real conditions, like pesticides, highly toxic components and small organic molecules, including toxins and endocrine disrupting chemicals.

Biosensors used in environmental monitoring can be categorized as optical (including optical fibre and surface plasmon resonance biosensors), electrochemical (including amperometric and impedance biosensors) and piezoelectric (including quartz crystal microbalance biosensors) based on their transduction or as immunosensors, aptasensors, genosensors and enzymatic biosensors based on their recognition elements, respectively when are used antibodies, aptamers, nucleic acids, and enzymes. The majority of biosensors in environmental monitoring are recognized as immunosensors and enzymatic biosensors, but the development of aptasensors has recently increased due to the beneficial characteristics of aptamers, like ease of modification, thermal stability, in vitro synthesis and the ability to design their structure, to differentiate targets with different functional groups and to rehybridize.

Study on the design of biosensors for the monitoring of organic pollutants, potentially toxic elements and pathogens in the environment has led to the sustainable development of civilization due to the environmental pollution issues confronting human health. Various chromatographic techniques (such as gas chromatography and high-performance liquid chromatography combined with capillary electrophoresis or mass spectrometry) are conventional analytical methods used for environmental monitoring of pollutants, but they require costly reagents, time-consuming sample pre-treatment and costly equipment. Therefore, for monitoring pollutants responsible for adverse effects on habitats and human health, more sensitive, cost-effective, fast, easy to function, and compact biosensing devices are desperately needed to overcome the magnification of environmental issues. In the case of accidental release of pesticides or acute poisoning, for example, common methods are not appropriate for in situ measurements where fast, miniaturized, and portable equipment like environmental monitoring biosensors is required. In this regard, the role of nanotechnology in the creation of rapid and intelligent biosensing devices is crucial for the success of environmental pollutant detection; most recent biosensors include nanomaterials and novel nanocomposites in their systems, which are beneficial for improving analytical performance, such as sensitivity and detection limits.

For the detection and monitoring of different environmental pollutants, biosensors, including immunosensors, aptasensors, genosensors and enzymatic biosensors have been documented using antibodies, aptamers, nucleic acids, and enzymes as recognition elements.

Pesticides

Pesticides are among the most significant environmental pollutants because of their large presence in the environment. Organophosphorus insecticides, for example, are commonly used in agriculture and represent a group of pesticides which, due to their high toxicity, are of immense environmental concern. Easy, responsive, and miniaturized in situ methodologies like biosensors have therefore been established as analytical strategies for their detection and monitoring, without the need for comprehensive sample pre-treatment.

Disposable amperometric enzymatic (acetylcholinesterase) biosensors were proposed for the detection of organophosphorus insecticides using paraoxon as a model analyte applying a cysteamine self-assembled monolayer on gold screen-printed electrodes. The disposable biosensors showed a linear spectrum of up to 40 ppb with a 2 ppb detection limit and a 113 μA mM cm^-2 sensitivity. Using the self-assembled monolayer, good analytical output could be due to the highly oriented enzyme immobilization. Recoveries of 97 ± 5 percent (n = 3) were reported after being tested in river water samples spiked with 10 ppb of paraoxon, indicating the effectiveness of such enzymatic biosensors. Furthermore, the use of disposable screen-printed electrodes dispenses with time-consuming methods like the reactivation of immobilized enzymes utilizing, for example, obidoxime solution and pralidoxime iodide (PAM) or the use of the renewable enzyme membrane needed for the second application of biosensors.

Nanoparticles based on iridium oxide have been used in the disposable enzymatic biosensor with tyrosinase based on low-cost screen-printed carbon electrodes for the detection of chlorpyrifos in river water samples. Linear biosensor response (0.01–0.1 μM) and low detection limit (3 nM) were reported, which could be due to the high conductivity of nanoparticles of iridium oxide and tyrosinase efficiency. Recovery tests were carried out in river water samples with the addition of 0.1 μM of chlorpyrifos and recoveries of 90 ± 9.6 percent were obtained with a residual standard deviation (RSD) smaller than 10 percent (n = 3) to demonstrate the applicability of the biosensor.

Acetamiprid was detected by colorimetric aptasensors and water samples by impedimetric aptasensors in real environmental samples, like fresh surface soil samples. A linear range of 75 nM to 7.5 μM and a detection limit of 5 nM were observed with the colorimetric aptasensor, while a wider linear range (50 fM to 10 μM) and a lower detection limit (17 fM) were observed with the impedimetric aptasensor. Gold nanoparticles, multi-walled carbon nanotubes (MWCNT) and reduced graphene oxide nanoribbons were used in that biosensor as a composite to sustain the electrode surface acetamiprid aptamer, which could be responsible for higher electron transfer and improved analytical performance of the biosensor. A related detection limit (33 fM) was observed by an aptasensor based on silver nanoparticles anchored on nitrogen-doped nanocomposite graphene oxide constructed for acetamiprid detection in wastewater samples.

Pathogens

The existence of pathogens in environmental matrices, and especially in water compartments, could pose a serious risk to human health, and some biosensors have recently been suggested for monitoring the environment. For example, for the detection of metabolically active Legionella pneumophila in complex environmental water samples, rapid and precise optical biosensors based on surface plasmon resonance have been proposed. In one study, the detection principle was based on the identification of bacterial RNA by the immobilized RNA detector probe on the gold surface of the biochip. For signal amplification, streptavidin-conjugated quantum dots were used, and the detection period was approximately three hours, indicating the viability of the biosensing device for successful bacteria detection in the range of 10⁴-10⁸ CFU mL^-1.

Potentially toxic elements

The contamination by heavy metals and corresponding ions of the natural waters can pose significant risks to human health, and compact, low-cost, and rapid heavy metal analyses are a global priority concern. As a model target for testing an optical DNA biosensor for the detection of heavy metal ions that are extremely toxic and common pollutants in the environment, mercury ions (Hg²⁺) were used. The biosensor was compact, low-cost, and rapid with in situ screening of Hg²⁺ in natural waters in less than 10 min. The detection principle is focused on the capacity of certain metal ions to bind selectively to certain bases to form stable metal-mediated DNA duplexes; in the case of Hg²⁺, thymine bases can be selectively coordinated to form stable thymine-Hg²⁺-thymine complexes. In the detection range between 0 and 1000 nM, a detection limit of 1.2 nM was achieved, which is lower than the maximum value requested by the United States Environmental Protection Agency (10 nM)

For the detection of Pb²⁺ in water samples (pond and lake water samples) using DNAzymes/carboxylated magnetic beads and DNA aptamers, two fluorescence based optical biosensors have recently been suggested. The detection limits of 5 nM and 61 nM, respectively, were observed by biosensors based on DNAzymes and DNA aptamers, with a respective linear detection range of 0 to 50 nM and 100 to 1000 nM. The use of label-free unique dye (SYBER Green I), which was intercalated with double stranded DNA, showing strong fluorescence intensities, as seen in Figure 5. Moreover, the absence of biosensor fluorescence intensity is observed only with the dye (curve a). With the DNAzyme + Pb²⁺ (curve b) the fluorescence intensity increases with the addition of the dye + DNAzyme + Pb²⁺, illustrating the sensitivity of the biosensor towards Pb²⁺.

Figure 5. Fluorescence emission spectra for detection of Pb²⁺

Toxins

Harmful toxins like brevetoxins and microcystins are created by the eutrophication of aquatic systems by the algal blooms of cyanobacteria, and thus accurate and cost-effective systems are needed for the early detection of such toxins. For the sensitive detection of brevetoxin-2, a marine neurotoxin, an electrochemical aptasensor has been used composed by gold electrodes functionalized with cysteamine self-assembled monolayers. A detection limit of 106 pg mL^-1 was achieved and strong selectivity was observed for brevetoxin-2 against other toxins of various groups, like okadaic acid and microcystin. The feasibility of the aptasensor for detecting brevetoxin-2 in real samples was achieved by analysing shellfish and strong recoveries (102-110 percent) were reported, indicating no interaction with the aptasensor response from the shellfish matrix.

Endocrine disrupting chemicals

In water samples, bisphenol A was detected as an endocrine disrupting chemical by aptasensors based on the fluorescence principle with functionalized aptamers (fluorescein amidite) and gold nanoparticles and based on evanescent-wave optical fibre. The evanescent-wave optical fibre aptasensor was compact and found to be rapid, cost-effective, sensitive and selective for the detection of bisphenol A in water samples, with the benefit of no requirement of any pre-concentration or treatment steps.  Furthermore, the aptasensor can be reused for 90 s by regeneration with a 0.5% sodium dodecyl sulphate (SDS) solution and further washing with a phosphate buffered saline (PBS) solution (pH 7.2) for over a hundred assay cycles without any noticeable loss of efficiency. Similar detection limits (0.1 and 0.45 ng mL^-1) were observed in both optical biosensors where the DNA molecule probe, which is the complementary sequence of a small fraction of the bisphenol A aptamer, was adsorbed by electrostatic interaction in the surface of gold nanoparticles and covalently immobilized on the surface of the fibre. Lately, for the detection of bisphenol A in river water samples using molybdenum carbide nanotubes, another fluorescence-based aptasensor was proposed. With such a label-free, inexpensive, and easy to use aptasensor, a low detection limit of 0.23 ng mL⁻¹ has been obtained. The specificity of the aptasensor was evaluated by analysing other molecules with structures similar to that of bisphenol A (e.g., 4,4J-biphenol, bisphenol AF, and 4,4J-sulfonyldiphenol) and only background signals showing high specificity for bisphenol A were identified for these molecules.

A disposable and label-free electrochemical immunosensor based on a field effect transistor with SWCNT has recently been employed in seawater samples for assessing another endocrine disrupting chemical – 4-nonylphenol. The immunosensor has a high reproducibility (0.56 ± 0.08%), an average recovery of 97.8% to 104.6% and a low detection limit (5 μg L^-1), which is lower than the recommended maximum concentration of 7 μg L^-1 specified by the corresponding regulations. In seawater samples such as 4-nonylphenol, the biosensor could be used to detect hazardous priority substances, even at low concentrations and with an easy and low-cost methodology.

Other environmental compounds

New, fast, and accurate analytical methodologies have been needed for the early detection and monitoring of various other hazardous compounds liberated during algal blooms. Due to the excellent sensitivity and specificity of nucleic acid probes to their complementary binding partners, biosensors have been developed to detect algal RNA. For the enhanced selective and sensitive detection of RNA from 13 harmful algal organisms, an electrochemical genosensor based on screen-printed gold electrode was recently reported; the genosensor could distinguish RNA targets from environmental samples (spiked seawater samples) containing 10⁵ cells, considered to be the limit of detection.

Nowadays, new regulations are in preparation aiming to propose contact code information for specific fields and also for individuals to find alternative sources of energy.

The Green energy

Nowadays, new regulations are in preparation aiming to propose contact code information for specific fields and also for individuals to find alternative sources of energy. These alternative sources have to provide power for private and public buildings, and at the same time generate a low number of toxic compounds. The is the so-called” going green” approach. Different alternative types of energy have been designed, like solar and nuclear power, with the purpose to save the planet because the toxic emissions accompanying the production of the traditional ones are a huge problem since they affect badly world life.

Along with the widely investigated toxic actions of global warming in recent years, it is vague in parallel to the harm provided by other resources used in the production of food and maintenance of clean water. Society has referred to materials like coal, oil, and even kerosene to ensure the needed energy. The fossil fuels, coal, oil, and other resources used for power production emit harmful side effects. These fuels are non-renewable and contaminate the environment and the atmosphere, impacting the sources needed for the survival of the species inhabiting our planet. As these sources are naturally restricted, troubles for their shortages and access are growing, the worst among them is their harmful effect on the environment. So, the use of these conventional sources of energy contributes to global warming. Coal and oil outflow toxic gases into the environment, and in this way endanger general health rising respiratory problems, and diminish the quality of life.

Green energy will help to relieve and smoothen at least some of these problems, and the faster we move to renewable energy sources the better.

Currently, it is estimated that ICT consumes 1.15% of the total electricity supply. It is accounted that the total annual operational electricity consumption for ICT is 242 TWh in 2015. This sum comprises on-site generated electricity (27 TWh) and grid electricity (215 TWh). Besides, the global operational carbon emitted by the ICT sector in 2015 is about 169 M tonnes CO₂. It is equivalent to 0.53% of the whole carbon emission by the energy sector (32 G tonnes) and 0.34% of global carbon emission (50 G tonnes) in 2015. The electricity consumption in the ICT network increased by 31% from 2010 to 2015. This subsummes185 TWh rise for 5 years, which is corresponding to 1% of the total electricity grid supply. The operational carbon emission growth has been 17% for this period.

Applying widely the 5G in near future, the rate of energy consumption increase is going to be even greater.

Green Energy Provisioning for ICT

Today, reducing greenhouse gas (GHG) emissions is getting up one of the most important research subjects in Information and Communication Technologies (ICT) due to the disturbing growth of indirect GHG emissions coming from the tremendous use of ICT electrical devices. Thus, solving the ICT GHG problem is linked to improving energy efficiency through energy consumption reduction at the micro-level.

Research in this field is focused on microprocessor design, computer design, power-on-demand architectures, and virtual machine consolidation techniques. The micro-level energy efficiency method will bring an overall rise in energy consumption due to the Khazzoom–Brookes postulate (also known as Jevons paradox) that says: “energy efficiency improvements that, on the broadest considerations, are economically justified at the micro-level, lead to higher levels of energy consumption at the macro-level”. Therefore, it could be reasonable that reducing GHG emissions at the macro level is a more appropriate solution. Large ICT companies, like Microsoft which consumes up to 27MW of energy at any given time, have built their data centers near green power sources. Unfortunately, a lot of computing centers are not placed close to green energy sources. For this reason, green energy distributed network is an emerging technology, allowing that losses incurred in energy transmission over power utility infrastructures are much higher than those caused by data transmission. This makes relocating a data center near a renewable energy source a more efficient decision unless bringing the energy to an existing location.

Management and technical policies will be a decision to arrange virtualization, which helps to move virtual infrastructure resources from one site to another based on power availability. This will facilitate the use of renewable energy within the ICT network providing an ‘Infrastructure as a Service (IaaS)’ management tool.

Green ICT and ways of Greening ICT

Green ICT is a broad concept, which lacks a general definition. This concept includes the energy efficiency of equipment such as computers, servers, and monitors. Occasionally, it mentioned the production of ICT equipment as well as the recycling. In other cases, it includes ways in which ICT can be used to mitigate the environmental impact of other sectors. 

• Defining Green ICT

Green ICT has been defined in the literature as “the using of IT resources in an energy-efficient and cost-effective manner” or “an initiative to encourage individuals, groups, and organizations engaged in the use of ICT to consider environmental problems and find solutions to them”. Green ICT is dealing with the environmental impact of the ICT sector itself. ICT for Green reveals how ICT can be applied to make other sectors greener. The ICT sector gives about 2% of the world’s GHG emissions, mainly due to the emissions from the aviation segment. Although, this figure does not look so much, some authors consider that ICT sector emissions are the highest growing one with rising rates of 6% annually. Besides, the environmental impact of ICT is largely neglected, aviation begins to pay attention to the environment decades ago, but the ICT sector has only started to take care of the environment nowadays. Concerning the Green ICT, the main ICT used are presented in Fig. 2. For each of these categories of equipment, there are different options, which can be made to reduce the environmental impact. When discussing the environmental impact of ICT, the most debated topic is energy efficiency. Meanwhile, there is also a question about such estimation of materials used for production, and the way to be done.

Measuring the energy efficiency is the easiest metric to estimate the effect of green ICT, because of the simple way to determine the energy consumption. More energy can at times be used during the equipment production in comparison to its entire lifespan and this is the case for PCs. When producing computers, several metals like aluminum, arsenic, copper, and lead are used. Some of them are hazardous and create needs for handling the equipment, especially during the recycling. It is claimed that 70% of all hazardous wastes are e-wastes. There are regulations for e-waste recycling in a lot of countries, but informal recycling offers a cheap way to deal with this waste and unfortunately is practiced a lot.

Figure 2. Main categories of ICT used.

• Going green in ICT

The term ‘green’ is used in everyday language to refer to environmentally sustainable activities. Also, the term ‘green’ repeatedly is used as being sustainable. Both concepts are closely linked but are not identical and to be green is only a part of being sustainable. The United Nations commonly discuss three aspects of sustainable development: the social, economic, and environmental dimensions. The term ‘green’ fits the environmental aspect because both are often interrelated. From an environmental point of view, it is well understood and reasonable especially in the case of linking ‘green’ ICT with economic growth. Thus, there is a reason that sustainability becomes a factor for the rapid growth of the ICT sector; it favors economic growth, ensures wide access to new technologies, and enhances the efficiency of other sectors.

The sustainability or its environmental issues definition given in the UN report “Our Common Future” said that sustainable are those processes that “meet the needs of the present without compromising the ability of future generations to meet their own needs“.

To be ‘green’ in the ICT sector is partly about taking informed solutions for the way of the use of natural resources.

A good illustration of the term “sustainability “is the way of how today’s living can impact the lives of future generations in terms of lack of some natural resources, health problems for those working with production and recycling, as well as the impact on the future generations. So, dealing with ICT there are different ways to become green.

It is necessary to define ‘green’ technologies and ‘green’ behavior. Green technologies involve parts like virtual servers, allowing a higher rate of utilization to realize a saving of energy of up to 85%, compared to standard PCs. However, the technology that is used inefficiently will not be green. In this way, the employees can have a big importance on the environmental trace. Turning off the equipment after leaving the office, and using technology to make green other parts of life, like hosting video conferences instead of traveling, or sharing different equipment like printers between departments, are examples of green bearing in the workplace.

Being ‘green’ in the ICT sector and information management is not precisely the same as being ‘green’ in other sectors. Each sector possesses its environmental issues and mitigation strategies. The ICT sector is peculiar, as causing greening of other sectors and it is not sure how the large contribution can be obtained for reduction of the emissions and achieving a better environment. Nevertheless, this environmental impact of ICT should not be overestimated. To be ‘green’ in the ICT sector is necessary to become aware of production way and the use and recycling the ICT equipment to be obligatorily sustainable. One of the most important aspects of ‘green’ ICT are those concerned with conserving energy, and other resources, such as paper and rare elements. Rare and hazardous materials are used in the production of ICT equipment. Hazardous materials offend not only the environment but also the people working with the manufacture of ICT equipment and its recycling. All these things are linked with ICT and information storage having the biggest impact on the environment. If all equipment is used optimally, it is reasonable to diminish the impact on the environment as well as possibly to save finances. 

• The Importance of being ‘green’

Nowadays to be ‘green’ is significant as a business strategy, which is due partly to consumer understanding of environmental protection. Environmental management is a part of the strategic approach for several successful companies, to involve a new concept of ‘green’ management to answer this strategy. Besides, investing in ‘green’ innovations and environmental protection is beneficial to companies from a financial point of view. Being ‘green’ could increase a company’s competitive advantage, as well as bring new market opportunities, and thus make ‘green’ companies more profitable.

At the same time, the dangers of the so-called ‘green-washing’: “the focus must move away from an emphasis on image to an emphasis on substance” are a serious warning. Thus, ‘green-washing’ is the term assigned to companies that try to get the face of being ‘green’, but apply cosmetic measures, rather than actual changes in the way the organization operates. So, if organizations want to make a real ‘green’ change, it can get a positive effect on society. The greening of organizations can bring new investments to improve the environmental situation, creating jobs and wealth. It is considered that investments in ‘green’ ICT can give short-term economic support. 

• Benefits of going green

A major chance to support greening is cost scanting. Observing the ‘green’ information technology, it becomes clear that data centers and servers dispose a large amount of energy for keeping run and cooing down. ICT resources cannot be used in their full capacity (a utilization rate is about 12.5%). This figure indicates lack of efficiency in the ICT sector. It is found that 86% of the needs can be arranged by 26% of the current energy utilization and this indicates a big room for cost improvement. Also, another part of ICT can propose considerable saving opportunities in usage in an environmentally friendly way. When turning off printers, as well as other energy-consuming equipment, whenever they are not exploited, resources can be saved and the environmental impact can be reduced.

Besides these options, it is acknowledged that moving towards a ‘green’ knowledge society will require structural changes, suggesting that governments should help to enable this process, and doing so benefits for the society as a whole will be realized.

No conventional definition of ‘green’ ICT exists. ‘Green’ topics could be approached from the perspective of a ‘problem’ (focusing on reducing the emission) or from the perspective of a ‘solution’ (focusing on new green solutions). This is reflected in the approach to ‘green’ ICT. This approach is presented in Fig. 3. It encompasses two segments: greening of ICT and greening with ICT.

Figure 3. The approach to ‘green’ ICT

Greening of ICT in a narrower sense refers to ICTs with low environmental burdens, but using ICT as an enabler reduces environmental impact across the economy outside of the ICT sector. Green ICT, as greening with ICT, is a new concept and even the leading countries and stakeholders have only about few years of experience. It is important to note that both the traditional ‘problem’ approach and the new ‘solution’ approach are needed. Pollution needs to be regulated and companies need incentives to address their emissions. However, ensuring that the new generation of solution providers get the right incentives is equally important.

ICT can contribute to the reduction of energy consumption and gas emissions through:

• Inventing innovative energy saver systems, technologies and ‘smart’ devices, using ‘smart energy management’;
• Applying energy saver policies using renewable sources, solar energy and photovoltaic, wind energy, bio-fuel, bio-climatic technology, anti-pollutants technology, etc.
• Recycling and reducing e-waste such as old IT systems, chips, PC, hardware, printers, mobile phones, etc.

About 40% of the total energy consumption is due to households. That is why, innovative ‘smart houses’, constructed by green materials, and green architecture exploiting innovative energy sensors are needed. In this context, ICT systems can achieve to measure, manage and reduce electricity consumption and air-conditioning requirements. During the last decade, technical and industrial product manufacturers were essentially obliged to change the direction of their energy consumption, as a result of the economic crisis in addition to the increased environmental awareness of the public. The concern is taken by the producers towards energy reduction via every computing device, from the laptops and mobiles to the data centers, and will be presumably successful. Consumers show their preference for smart devices, new less energy-consuming technologies, renewable energy sources, and updated, more efficient cooling systems with improved energy management software. These products are equipped with official certification to meet or exceed efficiency guidelines.

• Ways of Greening ICT

It is possible to use ICT in a way that reduces stress on the environment in comparison to the traditional ways. This can be done through new technologies, techniques, and strategies that allow the consumption of less energy and resources. An important part of the ICTs job is to save information. The need for storage is rapidly increasing because of the growth of Internet usage, new laws and regulations, arranging the rules for keeping the information, and scientific computing. The final part of the stored information is collected in data centers. These data centers use enough energy to partially shift the positive effects that ICT can have on society, for which it is claimed that “a fraction of energy savings in ICT and networks could lead to significant financial and carbon savings”. To reach energy efficiency in information storage, it is necessary to choose hardware with better energy efficiency or saving energy methods for the equipment use, which are suggested below.

During the last few years, there is a tendency of awareness rising regarding the impact of modern societies on the environment. A lot of environmentally important factors like energy consumption or e-waste are caused by the application of ICT but at the same time, this technology also could solve some other environmental issues. The dual nature of the issue is approached from an integrative perspective with the creation of the Green Computing concept. It is introduced in 1992 by the United States Environmental Protection Agency starting the ‘Energy Star’ programme. In the beginning, it was enforced on various products such as computer monitors, television sets, and air conditioners. The first well-known result of green computing was the sleep mode option of computer monitors consuming low energy in case user activity is lacking after a certain period. Today green computing gathers a lot of other concepts like confirming computer hardware using, virtualization software, cloud computing or, magnify the energy efficiency of data centers. Green Computing gathers technologies that can contribute to both decreasing the environmental impact of ICT (‘Green IT’ – greening of ICT) and applying information systems (IS) diminishing the environmental impact of ICT consumables (‘Green IS’ – greening by ICT). This integrative vision combines two complementary approaches, presented in Fig. 4.

Figure 4. The integrative vision for Green Computing

The practical implementation of the Green IT and Green IS can be clarified through the following conceptual value models.

Green IT: Value Model

The Green IT value model can assist to reach the goal of environmental sustainability. This conceptual model is grounded on four elements, as shown in Fig. 5.

Figure 5. The Green IT value model

Green IS value Model

The Green IS value Model is important for Green IS acceptance and its impact on the firm’s environmental enforcement. While companies are under permanent suspense from different regulators, clients, and competitors, some of them are ready to cancel efficiency and effectiveness for environmental issues. Green IS investments to fulfill sustainable business experiences are intended to raise turnover and/or income.

Green IS adoption by a company staff (senior managers) is investigated and explained through a model that describes perception as determined by three basic factors. Three types of strategic initiatives have to be taken into account for IS adoption. All of them are depicted in Fig. 6.

Figure 6. The Green IS value Model

This model could be put into action through a strategy for application of variety of technologies and techniques, like video and teleconferencing, emission management systems, etc.

A framework for management and application of Green IT and Green IS can be established that encompass variety of technologies offering opportunities for reducing the negative environmental impacts in activities by producers and consumers that use ICT. Among these Green Technologies are the following.

Cloud computing

A lot of organizations apply a new computing paradigm – cloud computing, to optimize usage and minimize the cost of their computer servers. In this way, previous costs linked with setting up the IT infrastructures are omitted. Cloud computing allows linking shared infrastructure and balancing IT resources for computing tasks in real-time while reducing gas emissions and maintaining the levels of service. Cloud computing relies on sharing of hardware and software resources that are shared by multiple users and dynamically reallocated per demand. This ‘green’ technology removes ultimately the need for a company to have an on-premise data center, which has a positive effect on the natural environment and its resources. To date, many vendors provide Green IS-focused cloud services and are experiencing significant financial growth rates per annum.

Computer power management

To save energy in computing, a common action is turning off the equipment in case it is not in operation. There is a so-called open industry standard “Advanced Configuration and Power Interface” (ACPI 2) that represents an advanced Green IT practice. It allows direct power control of the computer operating system and its underlying hardware. This standard automatically rules out components like monitors and hard drives when the inactive period of the equipment takes place. The computer power savings device includes different sleep modes of the monitor, hard disk, system standby and hibernation, and different CPU power states.

Data Center Design

Data centers consume a big percentage of energy, more than 100 times than standard commercial buildings. Thus, the efficient energy recycling design of data centers, like recycling of waste heat, gives a considerable positive impact on energy safety and can be used in the following areas:

• IT systems: increase hardware usage (through virtualization, see below); allow computer power savings modes; buy energy effective tools (e.g., computer power supplies, computer processors, solid-state storage devices, terminal servers);
• Main power systems: power management parts (hardware and software devices for optimizing work and power); rising the usage of renewable energy; use of natural light instead of electricity;
• Cooling systems;
• Air management.

IT Virtualization

The IT virtualization refers to the separation of IT resources through server virtualization and storage virtualization. The server virtualization means operation of many logical computer systems on one physical hardware, and the storage virtualization means summing physical storage from many network memory-tools, on which to be put a single storage device managed from a central console. The IT virtualization decreases costs for hardware, diminishes energy consumption and physical space use. At the same time, it refines software testing and spreading and rises the versatility of hardware investments. Also, it can help in work-sharing: the servers are either busy or put in a low-power sleep state. Thus, virtualization is one of the main approaches for organizations to implement environmental sustainability into IT practices and business.

Material recycling and e-waste

Exploring proper recycling of IT techniques, e-waste is reduced and harmful elements like lead, mercury, and cadmium are discarded from the natural environment. Then it they can be reused and de novo production might be omitted. The process of materials recycling is feasible nearly for any computing device and accessory, such as hard disks, printer cartridges, and batteries. In this way, persons and business organizations can extend the life of IT equipment by upgrading tools instead of just changing them.

Smart grid and smart matters

The Smart Grid technology encompasses hardware and software that ensures more effective exploitation of actual infrastructures for the generation of electricity, its transmission, and distribution. This is an updated version of the electricity delivery system, automatically acting on information flows. The task is to make better the efficacy, safety, and sustainability of the yielding and spreading of electricity by load balancing and peak load management. Devices on the network possess sensors to collect data (power meters, voltage sensors, fault detectors, etc.). Such a device is the Smart Meter, that makes use of digital communication between devices connected to the grid. The collected data relates to energy production and consuming behaviors of both suppliers and consumers. In that sense, real-time information exchange between producers and consumers helps to better control energy demands and reduces the need for energy surplus during peak hours. Tools on the network have sensors to gather data (power meters, voltage sensors, fault detectors, etc.). They read the energy (electricity, gas, etc.) consumption in defined periods and daily sends data back to the public utility e.g., for monitoring and cost estimation. It can also be used to provide information about energy consumption and to set real-time energy prices to consumers. A key feature is automation technology that lets the public utility adjust and control each device from a central location. Benefits include handling alternative sources of electricity (e.g., solar and wind power), smart control for eco-friendly buildings, and in due course integrating electric vehicles onto the grid.

Within the ICT industry, there are two main segments:

• Telecom infrastructure, i.e., telecom networks comprised of base stations and access points that provide connectivity to devices (human-centered or machine-centered);
• Mobile devices/terminals, that are communicated by connecting to the infrastructure (e.g., mobile phones, tablets, sensors, actuators, vehicles, drones, etc.).

In the future, billions of devices/terminals will be connected to millions of base stations. Although both segments (network infrastructure as well as devices/terminals) would benefit from renewable energy, the role of renewable energy is much greater in the network segment due to the following reasons:

• Energy consumption of base stations (telecom infrastructure) is much greater than the energy consumption of devices/terminals;
• Global network coverage is important to realize the envisioned networked society and internet of things;
• Base stations have a larger size and are expensive. It is affordable to integrate a renewable energy system with each base station.
• Base stations need reliable and continuous power provision unlike devices (e.g., mobile phones) that can be charged whenever power is available.

To comprehend the future green ICT trends, it is important to understand not only the history of green but also the history of ICT. For the last 20–30 years the ICT infrastructure has been built, the performance and density will continue to improve and increase. However, a turning point has now been reached. The current threshold is similar to the turning point all industrial eras have experienced. During the installation phase, new solutions are used to increase the efficiency in the old system, during the deployment phase the new system reaches maturity, allowing it to deliver entirely new solutions. Initially, the transformation happened in the “information sectors”, within e.g., music, video or book sectors, etc., and now we start to see the first signs of a serious change in the “heavy sectors”, such as car and mobility, construction, agriculture, and retail sectors, as well as in basic business models.

The shift from improving existing systems to providing new solutions is supported by two trends of ICT development and ‘green’ ICT that are important to understand.

• (1) the ICT companies are now influential economic players. For the first time in history, an ICT company – Apple – was the largest company in the US. Apple overtook Exxon Mobile, demonstrating that ICT companies can no longer be ignored by policymakers.
• (2) the ICT companies are now part of a ubiquitous network that is connecting almost everyone and almost everything on the planet. Nowadays, more people are connected than during any other time in human history. By 2020, there are about 50 billion connected devices, and the society is gaining access to data and experience transparency that is fundamentally different from what any society has ever experienced before.

One of the major challenges is that the new ‘green’ ICT solutions have to compete in a regulatory environment encompassing regulations created for the 19th-century industrial structure. It has also to deal with the predispositions among people unfamiliar with the speedy development of ICT solutions. In fact, the current technological development is so fast that society members of any kind – from policymakers to business leaders, to economic experts are witnessing how the whole procedure – from an idea to full-scale implementation, is taking place just for few decades. To clarify the situation, the phases of a long-term disruptive solution must be studied. At the beginning, something triggers an idea that spreads, e.g., the first personal computers. These brought about next ideas, such as paperless offices, virtual meetings, etc. All these activities excited people. After a while, working prototypes were introduced and many companies invested in very expensive prototypes of videoconference equipment. The technology was too new and no viable business model was used, instead, these prototypes were bough and managed by the companies themselves. Progressively, many decision-makers had been excited by the idea of ICT as a disruptive force in different areas, that they finally thought it would never come to happen.

A trend today is that policymakers do not consider significant changes that will be made by ‘green’ ICT. Many are still planning to invest in new coal power plants because they use the same economic model as they used previously. For instance, Siemens Germany has announced that they support a 25% target for renewables and are ending their nuclear power business.

The history of ICT’s development shows that society now is at an inflection point where ICT solutions move towards creating new solutions instead of making old systems better. Two important trends concerning ICT development could be pointed out:

• (1) The fact that ICT companies now are economically powerful and serve as a source of both economic and political capital.
• (2) ICT solutions and companies now are so abundant that new clusters of solutions providers can emerge. It is important to understand what ICT solutions actually can deliver.

‘Green’ ICT includes the use of ICT solutions to support smart growth. Consequently, to observe ‘green’ ICT, the context of current ‘green’ ICT trends should be comprehended. While until the 21^st century, ‘green’ was seen as nature conservation or pollution control, a significant shift took place at the beginning of the 2000s. A focus moved from a problem perspective (pollution control) to a solution perspective and a new generation of business leaders saw the opportunity to link the need for resource efficiency and sales of new products and services.

A parallel shift is observed in the ICT development. It moves from improving existing systems to providing new solutions. New ICT solutions were created to support energy efficiency and ‘green’ growth. One of the most popular examples for ICT-driven solutions are the e-books, smart grids, electric cars, online meetings, etc.

It’s positive that many citizens have begun to realize the concept of human-caused climate change and resource depletion. They consider as well the imperative necessity of acting on this matter. This understanding has led many people to make changes of their personal lifestyle. The “living green” tendency includes many aspects such as green constructions, renewable energy use, energy-saving at home, the extended use of eco-friendly products, a recycling approach. Here to add are the so-called sustainability checklists, designed to help households to assess how sustainable they are, and to offer suggestions for increasing home sustainability. Moreover, clever use of e-services can be a tool for less energy consumption in everyday life and at work. For instance, this is the case of paper use – the nowadays correspondence is substituted by digital formats using the Internet and smart devices. The production and distribution of new products and services show the tendency for minimization of the needed energy, estimated by carbon footprint. Another example is the substitution of traditional conferences with online ones that impose a direct positive effect on environmental protection and reduction of the GHG emissions because of reduced transportation services. It is reported that teleconferences can avoid the production of approximately 540.000 tn CO₂ per year; this is the cost of the air transportation of people.

The use of ‘Green’ ICT tools and services through broadband/5G Internet contributes to the environmental and societal welfare with the decrease of cost and time to access government offices (24/7 services), energy savings (no transportation), and restriction of pollute emission (carbon footprint). Similarly, in the sector of e-commerce and e-business new innovative business solutions are in favor of either the entrepreneur or the final customer.

Nowadays, ICT plays an important role in the environment protection and fighting climate changes. It has attracted considerable attention of diverse types of international forums.

Introduction

Nowadays, ICT plays an important role in the environment protection and fighting climate changes. It has attracted considerable attention of diverse types of international forums. Temperature and sea level rising, as well as the floods incidents and storms are undoubtfully impacting climate change, and influencing also the balance of the ecosystems, water and food supply, public health, industry, agriculture and infrastructure. The measures to combat climate change are focused on strategical aims like: i) energy efficiency enhancement; ii) increase the part of energy used from renewable sources and assure the trustworthiness of energy supplies; iii) ensure the supply of energy products and services, and sustainable production of green products.

The energy market today is undergoing serious reforms due to the introduction of new advanced energy technologies. They cause continuous environmental problems, rising needs for European and international cooperation. In this aspect, various intergovernmental agreements have been concluded to sharp and harmonize the organizational and legislative framework of the energy markets. Along the increasing attention for global climate change and related to the energy markets, the green Information and Communication Technologies (ICT) has been proposed as one, in which the environmental impact is taken into account in the design of new systems and technologies.

The topics of “Green informatics” and “Green ICT’’ are frequently discussed and the interest in ICT’s potential needs to be better appreciated and to focus the attention it deserves. The Green Informatics includes design, construction, and information diffusion techniques and offers optimization of environmental governance, in its efforts to save the natural environment. In this way, it contributes to successful management of the natural resources regarding sustainability, taking into account as well the energy requirements, in particular the alternative energy sources.

The web technology and broadband Internet along with web-based projects are penetrating in a great speed our society and a huge amount of information moves across the WWW worldwide. The Green Informatics are ICT tools, services and technologies deal with green practices and green manners either in the ICT industrial sector or with the ICT users. This can contribute also to the preservation and recovery of the environment as well as to the promotion of the quality of human life. Thus, the concept for ‘’Green Informatics’’ has turned into a synonym to eco-friendly technology and software tools like Virtualization, Recycling and Telecommuting.

At present, ICT unifies the electronic services (e-services) – broadband network infrastructure – mobile services, and wireless technologies. This mergence led to the development of instruments, products, services and technologies with increased social network opportunities, available 24/7, worldwide in all sectors of human life.

Broadband has been the entrance to the networking economy. Its abilities to convert the daily processes into work and life opens new business prospects for development nowadays, when a lot of countries are fighting to save their economies during global economic crisis.

The services for stabile permanent access to Internet assure reliable delivery with a great speed of Internet of high quality almost all over the world. Part of the web-based products commonly used to assure e-services are e-learning, e-working, e-banking, e-voting, e-government, e-commerce, e-shop, e-research, e-medicine and e-payment. Recently, useful mobile broadband services (m-services) adapted to the needs of the people were set up. They combine elements of user-generated content with network-based promotion. Through modification of economic and social measures, the mobile technologies support the sustainable development through green banking, green commerce, green governance, green constructions, etc.

An analysis of the global trends in green ICT has been performed with the purpose to find out what are the predominant trends in green ICT policies at global scale from medium- and long-term point of view. The analysis was carried out applying a desk research approach. First, relevant documentation related to green ICT was identified and, second, based on this documentation, the corresponding green ICT related policy trends at the EU and global level were outlined. The documentation set encompasses variety of EU and OECD strategy documents (e.g., OECD Green Growth Strategy, EU 2020 strategy, Digital Agenda etc.), as well as on researches and case studies performed before.

Green ICT advancement: global level policy

Both green ICT and greening with ICT comprise a new concept that has been on the economic and societal agenda since a decade. The area of greening with ICT is so new that it is hardly possible to launch a good practice for a single country to be securely followed. Most policymakers, major researches and business groups unambiguously declare that the greening with ICT is significantly important. However, the real programmes and policies at governmental level, NGOs’ work, research at universities, business initiatives, etc. are rather concentrated on the direct effects then on the long-term impacts.

A number of studies have shown that the majority of the initiatives at both governmental and business level focus on greening of ICT not greening with ICT. A study, performed by the OECD, published in June 2009 showed that most “Green ICT” initiatives concentrate on the direct effects of ICTs themselves rather than tackling climate change and environmental degradation through the use of ICTs as an enabling or “smart” technology”. The OECD analysis showed that the government programmes include initiatives to consider the enabling effects of ICTs. The ICT applications used for the dissemination of environmental information, for smart transportation, grids, and buildings are the most commonly promoted. However, software for energy optimization or smart engines have been less indorsed.

There is a gap between the policymakers and ICT companies that want to support a good image in front of the society, who focus on greening of ICT, and the needs for implementation actions that will lead to greening with ICT. In this context, solutions are necessary to be implemented by the institutions and frameworks in the form of new rules and regulations to support greening with ICT.

There is a variety of opportunities and challenges ahead the policy makers and businesses stakeholders along this implementation. To be best understand, these possibilities and challenges must be considered in respect to the main ICT players contributing to both greening of ICT and greening with ICT ideas. These interrelations are depicted in Fig. 3.

It can be seen that the majority of policy makers, foremost researches and business groups definitely indicate that the greening with ICT is meaningfully more important than greening of ICT.

The new concept of greening with ICT most commonly does not require only business relations but policy makers that create a new legislative framework and relevant guidelines for its implementation. However, currently the real initiatives of the business and the actual policies still focus on greening of ICT, persuading the direct effects of it.

Figure 3. Main ICT players contributing to greening of ICT and greening with ICT ideas

A global trends analysis has been performed to make an overview of the long-term tendencies in global policy making in respect to green ICT. A representative selection of the most relevant and comprehensive documents worldwide has been evaluated. It is assumed that within last two decades, greening with ICT has moved ahead from being an almost fiction idea into being an important subject. In the 1990s, greening with ICT matter has not been included in global strategy documents or policy making. The role of ICT in sustainable development had shaped clearly among thought leaders at the beginning of the new 21^st century. However, it was still more or less overlooked by both the policy makers and the business. The reason for this underestimation was grounded on the fact that the executive power was given to leaders from ministries of environment, and their efforts, and solutions, were sector-focused.

However, at that time the changes in policies on strategy level has started to officially recognize the businesses as an active party in solutions development; the power of ICT in supporting a more environmentally sustainable development was also acknowledged. Most governments and organizers that had mainly focused on the building of ICT infrastructure and the standards and rules its operation requires, embarrassed the new idea that ICT could be used to support an environmentally sustainable development. Accordingly, the companies have started to be seen as solution-generators that contribute to accelerate sustainable development instead of pollution-makers, which should reduce their emissions.

Starting from 2007, first attempts to include governments and businesses in a discussion about greening with ICT were organized. A year later, the chair of G8 brought green ICT to the forefront of the discussions’ agenda for the first time. The G8 leaders united around the immediate necessity the world to diminish carbon emissions, contributing strongly to global warming, by at least 50 percent by 2050. It was then the issue of green ICT was opened and OECD and EU confirmed the tendency through increased focus on greening with ICT.

In this way, greening with ICT has been acknowledged as a policy area. However, between the new ideas generated and their practical realization, there is still an “implementation gap. Since not all the ideas become reality and the shift from words to actions does not take place very smoothly, the businesses are facing serious challenge how and when to make their contribution to the greening with ICT trend.

Greening with ICT strategy is growing more stable to become a significant element in the mainstream policy making. The global climate meeting in Durban, 2011 and the Rio+20 conference in 2012 were the first forums that indicated this. More and more leading countries want greening with ICT to become a part of the global agenda for planet saving. They recognize competitive advantage in developing and exporting greening with ICT solutions, and the greening with ICT is already deeply integrated into their policy making.

The leaders in greening with ICT

In general, all main international stakeholders are key players in the greening with ICT area. At present, however, there is no a single leader; by contrast, there are many players that are focused on the process of greening with ICT with varying intensity and success. Indisputably, OECD and the European Commission are very important stakeholders but many innovative ideas have been emerging from independent business coalitions. Thus, there is a tendency for greening with ICT by economic clusters that focus on implementation at a local level.

The modern industrial society is built through organization of the society around certain economic sectors. These sectors were created by establishing new clusters in the pre-industrial society, and nowadays are called industries, even though they are combinations of several different skills. Crossing the era of the post-industrial / knowledge-based economy, the society needs new clusters to guarantee the new supply chains with new materials and new productions methods, the to secure the new business models with fresh ideas.

An example for this transition and the advancement of the clusters to a leading position is the energy sector, in particular the renewable energy. In renewable energy sector traditional utilities failed to deliver solar and/or wind solutions. It is because a collaboration between construction companies and architecture one and new solutions are necessary, and they often require new business models.

Usually, the ICT companies are very often at the center of the new clusters. However, their largest customers most commonly are one of the biggest polluters. This is a great challenge to the ICT companies and they have to be transformative to issue new solutions that support the business clusters with innovative greening with ICT solutions.

Alternative approaches to greening with ICT

Traditional green strategies are hardy effective for generation of greening with ICT solutions. In fact, most greening with ICT solutions result from smart strategies that are in search of resource efficiency and innovation in diverse economic areas, e.g., construction, transport, power supply, etc. This requires an approach to greening with ICT subordinated to the global development, discarding synergies and old stakeholders / methods. This very approach is a non-green one, although it also targets greening with ICT. A good example for a non-green approach is the use of procurements, both public and done by companies. As a rule, the companies face “green” and “ICT” trough a one-sided and limited approach; they focus on greening of ICT. This is because ICT companies (those who are selling) have products to put on the market and make profit from them, and CIOs (those who purchase) are trapped by old-fashioned ways of thinking and are besides, are not responsible for solutions like teleworking, virtual meetings and development of new business models.

Both the providers and the requesters of “greening with ICT” solutions very often do so without knowing and/or taking care about the green benefits of the action. Two of the most typical examples of such lack of knowledge/care are Amazon and Apple. Bothe companies are great promoters of greening with ICT; Amazon has contributed largely to the dematerialization of world’s books and magazines, and Apple has dramatically changed world’s music industry and made it more resource efficient. In the same way, smaller companies like Skype and Viber have progressively transforming the business models and habits without regarding their green activities.

The lack of cooperation and understanding between those that know and value the ICT opportunities (ICT companies and CIOs) and those that make new products and services is a big challenge. The problems are multiplied by the lack of strategies and definitions of greening with ICT. Some innovative “smart” solutions are considered “green” regardless of the actual results of their performance. For instance, the development and exploitation of smart grids is a trend where the transformative potential of the new ICT solutions, such as smart grids, is jeopardized by the traditional stakeholders that rule the agenda: the power utilities label their solutions as “smart”, although they continue to use old business models and large-scale utility structures.

In brief, greening with ICT solutions is mainly directed by smart strategies not by green demand or green policies.

Green informatics contribute to the environment and environmental sustainability in the following areas:

• Reduction of energy consumption and carbon footprint along production and use;
• Diffusion of information, education, and training to rise environmental awareness;
• Environmental projects and networks promotion through communication;
• Sustainable environmental governance.

Reduction of energy consumption and carbon footprint along production and use

The massive introduction of ICTs in everyday life has resulted among others in the increase of greenhouse effect, due to the ‘carbon footprint’ increasing. As per definition, carbon footprint (CF), known as well as ‘Carbon profile’ comprises the overall amount of carbon dioxide (CO₂) and other greenhouse gas (GHG) emissions (e.g., methane, laughing gas, etc.) associated with a product, along its supply-chain, end-life recovery and disposal. In respect to ICT, it refers to the energy needed and the pollution generated in ICT production processes and within the ICTs use (Fig. 4). The total amount of CO₂ emissions from the ICT industry progressively counts upstream. At the same time, ICT applications are recognized to possess enormous potential in contributing to different performances across the economy and society. They are the right tool of the strategies for the global environmental protection.

Figure 4. Carbon footprint in megatones of CO₂ from ICT sectors. Source: Bronk et.al., 2010

Diffusion of information, education, and training to rise environmental awareness

Diffusion of information, education, and training with the purpose to rise environmental awareness is an approach applied worldwide to help people be up-to-date and understand environmental issues and environmental policies.

The wireless/mobile) internet access is irreplaceable as a tool of information delivery for populations that are isolated or remoted and that lack an access to traditional channels, such as TV, radio, newspapers, magazines, etc.

There are numerous of internet sites, blogs, forums, social network groups, internet polls, etc. dedicated to delivery and sharing environmental information. These information sources are operating from local to international scale, and act as an open tribune for everyone to participate, to offer and share opinion.

Learning and training contribute to enhancement of people’s knowledge, skills, and awareness. Suitable learning/training software packages are those offering presentations and educational games, and educational e-services such as e-classrooms, e-learning, ODL, web-based learning, LLL, etc.

Projects promotion through environmental networks communication

The application of ICT for communicating different projects within environmental networks can be a useful approach for their successful implementation at local, regional, national, and transnational level. The accomplishment of environmental projects requires as a prerequisite effective communication among participants of various stakeholders, protected through innovative green informatics tools and services. Namely, green informatics makes safe information flow for the purposes of quick and reliable communication. Environmental networks comprise various stakeholders, all integrated through ICT-mediated communication (Fig. 4).

Sustainable environmental governance

Green ICTs have turn into a key factor for public sector’s performance because it promotes the advancement in the delivery of information and services and encourages the citizen participation in the decision-making process. In this way ICT helps the government to become transparent, responsible, and operative. The e-governance strategies, initiatives, and developments are grounded on the ICTs. In particular, the governance of natural ecosystems, natural resources and agriculture has to manage a wide range of connections between different environmental elements and decisions of local, regional, national, and international importance, and has to coordinate diverse administrative objects and players, and ICTs helps a lot for execution of these complex tasks.

Figure 5. Impact of green informatics to environmental networks communication

ICT impacts green and sustainability

EU has launched the initiative ‘ICT for sustainable growth’, a specific process that focuses on greening with ICT (in addition to greening of ICT). It has determined six policy areas of major priority that focus on Energy Efficiency, Water Management and Climate Change Adaptation (Fig. 6). Thus, it contributes to the development of a more sustainable Europe solving environmental problems and ensuring the sustainable environmental management.

The contribution of Green Informatics to the preservation and improvement of natural environment and resources is focused on the building of surveillance systems that aim to protect and restore natural ecosystems. In addition, it promotes ecosystems potential deployment and introduces prevention actions for its maintenance. For instance, forests and agricultural land are important to climate change mitigation because of the significance of their carbon stock and also for their exchange of greenhouse gases between the atmosphere, soil, and vegetation. The harvest of trees to supply book and newspaper industries leads to the emission of millions metric tons of CO₂ annually. Thus, the innovative tele-detection for forest fires, monitoring and alarm systems, GIS technology, etc., all contribute to sustainable forestry management.

Figure 6. ‘ICT for sustainable growth’ six policy areas.

The organization, access and management of the information in the environmental databases is an important factor within decision-making process. Since environmental projects have to manage huge multivariable data sets of interdisciplinary character (meteorological, geographic, biological, economic, etc. data), this has been successfully achieved through ICTs applications and is called environmental monitoring. The main procedure of environmental monitoring is presented in Fig.7. It is a useful tool that integrates geospatial technologies aiming to sustain agricultural and environmental observation networks and deploy agricultural and environmental applications

Figure 7. Wise management to environmental sustainability – Green Informatics contribution

The DSSs use defined parameters to provide wise management aiming to environmental sustainability and helping decision making process towards sustainable environmental management. These are Environmental databases, GIS, time-series, multi-variant, and multi-criteria analysis, expert systems, etc.

ICT and the Economy-Defining Technologies (EDTs): KBE/KBBE

The innovative technologies that constitute the principal technological basis of an economy, are called Economy-Defining Technologies (EDTs). EDTs are always inherent to the corresponding economy, and ICTs are definitely such technology.

Knowledge has always played a central role in any economy. However, in the Knowledge-Based Economy (KBE) knowledge has been liberated from its temporal and spatial constraints because of the ICTs. This is what allows knowledge to unfold its powers as a universal resource, leading to the KBE.

Grounded on this concept, OECD defines the KBE in the following way: “The knowledge–based economy is an expression coined to describe trends in advanced economies towards greater dependence on knowledge, information and high skill levels, and the increasing need for ready access to all of these by the business and public sectors.”

Knowledge takes predominance for both individuals and organizations in the KBE.

The Knowledge-Bases Bio-Economy KBBE presents a wide range of challenges to ICT. However, the area with potential highest impact of ICT for KBBE is the general and synthetic biology along the dimensions of education, research, and industry applications.

The needs of ICT-driven innovations, which are able to reduce energy and materials used while enhancing the efficiency of business systems, can generate wide opportunities for companies’ businesses. The said innovations include software applications (e.g., virtualization technology to implement power savings), and hardware applications (e.g., server with energy-saving properties). In addition, essential industrial infrastructure must be active in order to capitalize on the expanding global market for ICT-based solutions planned for improving the energy efficiency as well as tackling the climate change concerns.

Besides the economic benefits, adopting Green ICT practices in business operations can easily deal with climate change issues that are associated with greenhouse gas emissions. Additionally, it also described that Green ICT can play a crucial role in helping to promote the low carbon economy around the world. The ICT industry can also produce a green image while behaving as a responsible global citizen.

Green ICT and education

Green ICT at Higher Education Institution

Currently global warming and climate change are in the front of societal agenda. They turned into a common subject of discussion globally. Climate change consequences arise huge environmental problems and impact energy and industrial policies worldwide.

Green ICT, as a system of initiatives and strategies that reduce the environmental footprint of technology, is able to respond to the needs for implementation of climate change adaptation and mitigation actions. Hence, Higher Education Institutions (HEI) are forced to implement more sustainable approaches to ICT use. This necessity is introduced by the government, stakeholders and society as a whole. Green ICT implementation at University level has developed as key factor to reach the cost-effective solutions and sustenance of ICT.

Moreover, the HEI have deep moral responsibility to increase knowledge, skill and awareness, with the aim to create a sustainable future. Their role in mainstreaming society towards sustainability is indisputable. However, at the same time, they are facing some barriers in Green ICT practical implementation. Therefore, Green ICT is a multifaceted subject, which importance is progressively increasing towards understanding the role of ICT is enabling sustainable practices. For instance, green research and development activities can contribute to reducing environment impact of society by dropping the impact of ICT installations in telecommunication and data-centers, customer offices, homes through greening of ICT. At the same time, the impact of society can be reduced by providing various kinds of ICT services through greening by ICT. Thus, HEI need to transform education within sustainability prospect to be able to educate undergraduates to become the ICT engineers our future needs.

Green ICT practices in HEI

The SMART 2020 report stressed upon the capacity of ICT to monitor and maximize energy efficiency, not only within its own sector but also outside it, resulting in considerable emission and footprint reduction. Studies performed to analyze and review the evolution of Green ICT practices in different HEI have proven that the proper ICT deployment contributes to sufficient reduction of GHG emissions. HEI follow environmental sustainability (ES) practices to complete the strategic plans for environmental sustainability through organization of virtual classrooms, digitalization of paper documents, performance of video conference to reduce travel, use alternative clean sources of electrical power, etc.

 Constrains for Green ICT Practices in HE

There are various factors that obstruct the implementation of sustainability initiatives of HEI, associated mainly with institutional barriers. These constraints are complex: from old-fashioned contracts of educators, to shortage of equipment, finance and trained tutors, to inadequate environmental teaching methods, lack of motivation towards ‘green behavior’ of teaching staff and students in their approach of using ICT (e.g., by reducing print volumes, using conference calls to reduce unnecessary travel, etc.).

The main constraints that act as barriers in implementation of Green ICT at HEI are listed in Fig. 8.

Figure 8. Constrains for Green ICT implementation at HEI

Green ICT impact at governmental level

Governments are one of the primary users of ICT and impact substantially the ICT industry. Due to its potent influencing power, the governments must play a leading role in acceptance of Green ICT technologies, improving its operational efficiency, and encouraging societal environmentally-aware and sustainable culture. Thus, it is essential for the governments to establish close collaboration with the ICT industry, and there are several areas that the governments have to seek for better opportunities for the Green ICT implementation. These are outlined in Fig. 9.

Figure 9. Areas for governmental collaboration with the ICT industry and Green ICT implementation

This part deals with the advanced design of a Database. It explains the structure of a Database and how to make relations between Database tables.

Open access scientific ressources

Figure 1: Non-exhaustive list of available databases

This part deals with the common databases found on the market, whether they are free or proprietary. However, there are so many databases available (figure 1) that we cannot mention all of them. A choice had to be made and the ones presented below are the “most popular” or the “most frequently used”.

Commercial Databases

From the vast number of databases available on the market, we chose to present three commercial databases commonly used by the major companies and organisations.

SAP HANA

This database is designed by the European company SAP SE, founded in Germany. SAP HANA is a database engine that is column-oriented and can handle SAP and non-SAP data. The engine is designed to save and retrieve data from applications and other sources across multiple tiers of storage. SAP HANA can be deployed on-premises or in the cloud from a number of cloud service providers. This database is usually chosen by organizations that are pulling data from applications and are not under a terribly constrained budget.

Its main features are:

• It supports SQL, OLTP and OLAP.
• The engine reduces resource requirements through compression.
• Data is stored in memory, reducing access times, in some cases, significantly.
• Real-time reporting and inventory management are available.
• It can interface with a number of other applications.

Αs of January 2021, the currently supported hardware platforms³ for SAP HANA are:

• Intel-based hardware platforms
• IBM Power Systems

Αs of January 2021, the currently supported operating systems⁴  for SAP HANA are:

• Linux SUSE

Linux Red Hat

IBM Db2 Database

IBM Db2 database traces its roots back to the beginning of the 1970s when Edgar F. Codd, a researcher working for the company, described the theory of relational databases, and in June 1970 published the model for data manipulation. Today, it is a database engine that has NoSQL capabilities, and it can read JSON⁵ and XML files.⁶

The current version of DB2 is LUW 11.1, which offers a variety of improvements. One, in particular, was an improvement of BLU Acceleration (BLink Ultra or Big Data, Lightning fast and Ultra-easy), which is designed to make this database engine work faster through data skipping technology. Data skipping is designed to improve the speed of systems with more data than can fit into memory. The latest version of Db2 also provides improved disaster recovery functions, compatibility and analytics.

Its main features are:

• BLU Acceleration can make the most of available resources for enormous databases.
• It can be hosted from the cloud, a physical server or both at the same time.
• Multiple jobs can be run at once using the Task Scheduler.
• Error codes and exit codes can determine which jobs are run via the Task Scheduler.

The currently supported hardware platforms⁷ as of January 2021 for IBM Db2 are:

• IBM z/Architecture mainframe
• Intel-based hardware platforms

The currently supported operating systems as of January 2021 for IBM Db2 are:

• z/OS
• Unix
• Linux
• Windows

Oracle Database

Oracle Database is commonly used for running online transaction processing (OLTP) or data warehousing (DW). It can also mix OLTP and DW database workloads. Oracle Database is available on-premises, on-cloud or as hybrid cloud installation. It may be run on third-party servers, as well as on Oracle Exadata hardware on-premises, on Oracle Cloud or on a private Cloud at customer premises.

The first version was released in 1979 and its development was influenced by the research of Edgar F. Codd on relational database design.

Its main features are:

• It is a cross-platform database. It can run on various hardware across operating systems, including Windows Server, Unix and various distributions of GNU/Linux.
• It has its networking stack that allows applications from a different platform to communicate smoothly with the Oracle Database, e.g. applications running on Windows can connect to the Oracle Database running on Unix.
• It is an ACID-compliant database that helps maintain data integrity and reliability.

The currently supported hardware platforms are:

• Proprietary Oracle Database Appliance
• Sparc
• IBM Power Systems
• X64-based hardware platforms

The currently supported operating systems⁸ are:

• Unix
• Linux
• Windows

Free Databases⁹

If a database is free, this does not necessarily mean that no fees are charged to the user. It is true for some of the following databases, however, some developers choose to limit certain features and charge a fee to be able to unlock those features (refer to the first unit of the Basic Level).

MySQL

MySQL is an open-source relational database, which runs on a number of different platforms, including Windows, Linux, macOS, etc. A cloud version. MySQL can be used for packaged software, business-critical systems and high-volume websites.

Its main features are:

• It provides scalability and flexibility
• The tool has web and data warehouse strengths
• It provides high performance

It has robust transactional support

PostgreSQL

PostgreSQL is an enterprise-class open source database management system. It supports both SQL for relational and JSON for non-relational queries. It is backed by an experienced community of developers who have made a tremendous contribution to make it a highly reliable database management software. It runs on three different platforms, namely Windows, Linux and macOS. A cloud version is not available. PostgreSQL enables the creation of custom data types and a range of query methods. A stored procedure can be run in different programming languages.

Its main features are:

• It is compatible with various platforms using all major languages and middleware
• Standby server and high availability
• The tool has mature server-side programming functionality
• Log-based and trigger-based replication SSL
• It offers a most sophisticated locking mechanism
• Support for multi-version concurrency control
• It provides support for client-server network architecture
• The tool is Object-oriented and ANSI-SQL2008 compatible

PostgreSQL allows linking with other data stores like NoSQL, which act as a federated hub for polyglot databases.

Microsoft SQL

SQL Server is an RDBMS developed by Microsoft. It supports ANSI SQL, which is the standard SQL (Structured Query Language) language. However, SQL Server comes with its implementation of the SQL language, T-SQL (Transact-SQL). It runs on Docker Engine, Ubuntu, SUSE Linux Enterprise Server and Red Hat Enterprise Linux. A cloud version is available.

Its main features are:

• It provides integration of structured and unstructured data with the power of SQL Server and Spark.
• The tool offers scalability, performance and availability for mission-critical, intelligent applications, data warehouses and data lakes.
• It offers advanced security features to protect your data.

Access to rich, interactive Power BI reports, to make a faster and better decision.

MariaDB

MariaDB is a fork of the MySQL database management system. It was created by its original developers. This DBMS tool provides data processing capabilities for both small and enterprise tasks. It runs on three platforms, namely Windows, Linux and macOS. A cloud version is available. MariaDB is an alternate software to MySQL. It provides high scalability through easy integration.

Its main features are:

• It operates under GPL, BSD or LGPL licenses.
• It comes with many storage engines, including the high-performance ones that can be integrated with other relational database management systems.
• It provides the Galera cluster technology.

MariaDB can run on different operating systems and it supports numerous programming languages.

Oracle

Oracle is a self-repairing, self-securing and self-driving database designed to eliminate manual data management. It is an intelligent, secure and highly available database in the cloud that helps businesses grow. It runs on two platforms, namely Windows and Linux. A cloud version is also available.

Its main features are:

• Oracle Cloud is optimized for high-performance database workloads, streaming workloads and hyperscale big data.
• You can easily migrate to the Cloud.

It provides the services based on how you like to operate, in order to run Oracle Cloud in your data center.

Firebirdsql

Firebird is an open source SQL RDBMS that runs on Microsoft Windows, macOS, Linux and several Unix platforms, including HP-UX, Solaris and AIX. A cloud version is available. Firebird has development-friendly language support, stored procedures and triggers.

Its main features are:

• Firebird allows you to build a custom version.
• It is free to download, register and deploy.
• The tool has enhanced multi-platform RDBMS.

Provides a range of funding options from firebird memberships to sponsorship commitments.

This section is dedicated to further exploring the open access databases used in science and how to use and get benefit of the existing knowledge.

Overview of databases in the scientific world

Existing databases dedicated to science and how to use them

As previously mentioned, sharing, integrating and annotating data is a crucial part of biological research as it allows researchers to reproduce the examination and interpretation of experimental findings. Although it is thought that bioinformaticians and computer scientists are responsible for these actions, life scientists have an equal role in promoting data integration, since they are the ones that generate these types of data and are usually the end users.

Data integration is defined as the process of combining data from different sources in order to offer users a unified view of such data. In computational sciences the theoretical frameworks for data integration have been categorised, based on the method used to integrate the data, into “eager” and “lazy”. According to the eager method, which is also known as warehousing, the data are copied over to a global schema and stored in a central data warehouse. The term “schema” refers to an organised and “queryable” approach for storing data. In the lazy method, the data are located in distributed sources and are integrated on demand in accordance with a global schema used for mapping the data between sources. The volume of data, the owner of the data and the existing infrastructure are the main factors that ultimately determine which of the two methods will be used for data integration. Moreover, in biological sciences, these methods may be applied in various different ways and used at a range of levels. As a result, six distinct and widely used schemata have been formulated for the integration of data:

• Data centralisation: The data reside in centralised resources. UniProt and GenBank are two examples of databases following this method.
• Data warehousing: data from a variety of sources reside on one central repository. Pathway commons is a database that follows this approach to integrate data.
• Dataset integration: In-house workflows access databases that are distributed and download data to a local repository.
• Hyperlinks: This approach enables users to access databases and tools in different fields of life science, thus promoting interoperability. ExPASy is an indicative example of a portal that is based on this data integration methodology.
• Federated databases: A translational layer is required in order for data to be integrated among heterogeneous databases. This means that data from the database are transformed to a commonly accepted format in such a way that they are able to be interpreted in the same way from a mapping service. The Distributed Annotation System (DAS), which is a client-server system, is an indicative example.
• Linked data: A network of interconnected data accessible online. Graphical user interfaces (GUI) that consist of hyperlinks, which connect associated data from numerous data providers and, hence, form a large system of Linked Data. BIO2RDF is an indicative example of a database that uses this approach as the basis for data integration.

Data centralisation, data warehousing and dataset integration are based on the “eager” theoretical framework, whereas hyperlinks, federated databases and linked data are based on the “lazy” theoretical framework regarding the way that is selected for data integration.

Data formats are described as an organised way for the demonstration of data and metadata in a file. Scientists began to store biological data in formatted files because the exponential growth of data created the need to analyse them using computer systems and databases. A problem that has arose in relation to file formatting is the emergence of various formats, even for the representation of the same type of data. In some cases, it has been observed that more than one format classes may be used to represent the data and metadata in a single file. Moreover, research has demonstrated that the most widely used format classes are: i) tables, ii) FASTA-like, iii) tag-structured, and iv) GenBank-like. The ideal solution to this matter would be for scientists to agree upon using a limited number of specific formats so as to simplify the process of data integration. The design of converters that have the ability to translate all the different classes of formats would also provide a helpful solution.

Currently, over 1,700 databases including data of biological interest are in use, according to the non-exhaustive list curated by the Nucleic Acids Research journal. In order to be deemed valuable for a specific purpose, all datasets that are present in a database have to be integrated and structured. The existing biological databases are comprised of information about a vast range of biology research topics, such as non-vertebrate genomics, protein sequence, human genes and diseases, DNA nucleotide sequence, cell biology, immunology, metabolic and signalling pathways, proteomics, etc.

As previously mentioned in the Basic Level, the classification of biological databases is dependent upon several factors, including the scope of data coverage and the level of biocuration. Nevertheless, their classification according to the type of data is one of the simplest and most comprehensive ways of categorising biological databases. Therefore, in the following section, these will be described as DNA, RNA, protein, disease, expression and pathway databases.

DNA databases

DNA databases focus on handling DNA data from numerous or a few particular species. The main purpose of human DNA databases is to establish the reference genome, to conduct profiling of human genetic variation, to associate genotype with phenotype and to identify human microbiome metagenomes. A DNA database example is GenBank, a publicly available collection of all the studied DNA sequences. As of February 2021, over 776 billion nucleotide bases in over 226 million sequences are available in GenBank (http://www.ncbi.nlm.nih.gov/genbank/statistics).

RNA databases

These databases include information about non-coding RNAs (ncRNAs), such as microRNAs and long non-coding RNAs (lncRNAs), which do not encode proteins. The purpose of RNA databases is to decode ncRNAs, of which lncRNAs are the most commonly studied, and to describe their functions and interactions. An RNA database example is RNAcentral, which consists of a unified view of ncRNA sequence data derived from a number of databases, some of which are Rfam, miRBase and lncRNAdb.

Protein databases

Protein databases were developed in order to create a vast compilation of universal proteins, identify protein families and domains, reconstruct phylogenetic trees and conduct profiling of protein structures. PDB, which consists of thousands of structures of biological macromolecules, is an indicative example of protein databases.

Disease databases

By definition disease databases include information about different types of diseases, but are mostly focused on providing data concerning various types of cancer. One of the most important cancer projects that has been developed is The Cancer Genome Atlas (TCGA), the objective of which is to gather a broad range of omics data, such as mRNA, SNP and methylation, for over twenty different forms of human cancer.

Expression databases

Expression databases may be utilised for a number of tasks, such as studying tissue-specific gene expression and regulation, storing expression data, detecting differential and baseline expression, and examining and reviewing expression information obtained from RNA and protein data. As an expression database, the Human Protein Atlas incorporates expression profiles for a significant percentage of human protein-coding genes derived from RNA and protein data.

Pathway databases

Pathway databases include data about biological pathways that can be utilised by researchers for the analysis of metabolic, regulatory and signalling pathways. A characteristic example of pathway databases is KEGG PATHWAY, which contains information regarding molecular interaction and reaction networks.

The National Center for Biotechnology Information (NCBI), part of the US National Library of Medicine at the National Institute of Health, has developed an integrated database retrieval system, which offers access to 34 different databases collectively containing 3.0 billion records, named Entrez. The global search page of Entrez (https://www.ncbi.nlm.nih.gov/search/) provides links to the web portal for each of the 34 databases. The Entrez system is easy to use because it allows users to download data in a variety of formats and to perform text searching using simple Boolean queries. Records are linked between databases on the basis of asserted relationships; these records can be represented in various formats. Moreover, users of Entrez have the option to download single records or batches of records. Some of the 34 databases that are part of Entrez are the following: PubMed (https://pubmed.ncbi.nlm.nih.gov), which contains scientific and medical abstracts/citations; BioSample (https://www.ncbi.nlm.nih.gov/biosample), which comprises descriptions of biological source materials; GEO Profiles (https://www.ncbi.nlm.nih.gov/geoprofiles), which includes gene expression and molecular abundance profiles; and, dbVar (https://www.ncbi.nlm.nih.gov/dbvar), which contains data from genome structural variation studies.

The data submitted to NCBI are derived from three sources: i) directly from researchers, ii) national and international partnerships or agreements with data providers and research consortia, and iii) internal curation efforts. Of note, NCBI is responsible for the management of the GenBank database and partakes in the International Nucleotide Sequence Database Collaboration (INSDC) in cooperation with the EMBL-EBI European Nucleotide Archive (ENA) and the DNA Data Bank of Japan (DDBJ).

As databases have proven to be a useful tool in many scientific fields, their use is steadily gaining ground in the healthcare sector. Nowadays, technological advancements in the area of data science have enabled healthcare professionals to compile, process and analyse health-related data, leading to the improvement of not only the delivery of care, but also the safety of patients and consumers. In order for these improvements to take place, relevant data must be gathered, stored and analysed in an efficient and secure manner, and exchanged across the different service levels present in a healthcare system. This has led to the development of Electronic Health Records (EHRs), databases which store patient data that can be accessed and utilised by healthcare professionals.

EHRs can be defined as medical databases that offer users, which in this case are healthcare professionals and administrative staff, access to health records. The most distinct types of EHRs are the Electronic Medical Record (EMR) and the Personal Health Record (PHR). EMRs consist of information, which is submitted by a single hospital department, an entire hospital or parts of the hospital. They can also contain information from a number of hospitals. Information to this type of EHR is normally added only by hospital staff. On the contrary, PHRs are managed by the patients, which are able to enter information. PHRs are described as electronic applications that provide a secure platform for patients to control and share their health data. The main difference between the two types of EHR systems is that, in PHRs, health records have to be presented in such a way that is understandable by the patient, whereas, in EMRs, the way health records are presented resembles health records on papers, since they are only accessed by healthcare providers.

The first EHR system became available in the 1960s mainly due to the build-up of unstructured and unused patient information over a period of several decades. Large organisations started to set up database systems in order to store and structure data into central repositories. These databases allowed the organisation and collection of data from many different sources, including pharmacies, laboratories, clinical studies, and constituents of clinical care, such as medication administration records. Currently, the implementation of EHR systems is mostly observed in high income countries. For example, the Health Information Technology for Economic and Clinical Health Act (HITECH Act of 2009) prompted the digitization of the healthcare delivery system in the US and the subsequent development of the Medicare and Medicaid EHR Incentive Programs.

The primary purpose for the creation of EHRs was the need to archive and structure patients’ records. They were later designated for billing and quality improvement reasons. As technological advancements took place, over the years EHRs became more inclusive, dynamic and interconnected. Nonetheless, compared to other industries, big data have not been used to best advantage in the medical industry. This has happened predominantly due to the poor quality of collected data and poorly structured datasets. Prior to the development of EHRs, medical research was based on disease registries or chronic disease management systems (CDMS). These repositories have significant limitations, since they consist of collections of data that are often related to only one particular disease. Furthermore, they cannot perform translation of the data or conclusions to other diseases and may include information from a group of patients in a specific geographic area. On the other hand, EHR data is largely varied, thus facilitating the analysis of complex clinical interactions and decisions.

The components of EHRs are different types of medical data, ranging from health records to raw sensory data. Medical data can be categorised into sensitive data or non-sensitive data. Sensitive data include patient information or can be associated with a patient. Non-sensitive data include sensory data, which are also called measurement data due to the fact that they are only comprised of samples of sensors, such as samples of an EEG measurement. Data stored in a medical database are referred to as metadata. The most common type of database used for storing medical data is the relational database, which presents data in the form of tables comprised of rows and a set number of columns. Some databases may include patient information, such as the medical history of a patient, or anonymised data that can be utilised in studies.

Medical data can be divided into several categories as described below:

• Medical and laboratory data: Healthcare workers can submit orders for medication or laboratory studies into a physician order entry system, which are subsequently carried out by laboratory or nursing staff. Examples of this category of data are prescriptions for medication and microbiology results.
• Billing data: This category of medical data is comprised of codes used by hospitals to file claims with their insurance providers. The International Classification of Diseases, constructed by the WHO, and the Current Procedural Terminology, sustained by the American Medical Association, are the most popular coding systems.
• Images: These may be radiographic images resulting from x-rays, echocardiograms and computed tomography (CT) scans.
• Notes and reports: These may be associated with the progress of patients. Discharge summaries also belong to this category. Findings from imaging studies are usually described in operative reports. Notes have to be partially structured using a templating system.
• Physiological data: This category of medical data contains vital signs, such as heart rate and blood pressure, as well as ECG and EEG waveforms.

Relational databases are most frequently used for medical data management and storage. They can be referred to as a collection of tables that are connected by shared keys. A database schema determines how the tables will be structured and their relationships. A simple medical database may contain four tables:

• Table 1: a patient list
• Table 2: a hospital admissions log
• Table 3: a list with vital sign measurements
• Table 4: a dictionary of vital sign codes and associated labels

Primary and foreign keys can be used in order to link the four tables.

The preponderance of healthcare databases provides limited access to data for various reasons, including privacy concerns and plans to monetise the data. Nonetheless, a number of open access health databases are available for public use, some of which are described below.

The Medical Information Mart for Intensive Care (MIMIC) database

The MIMIC database (http://mimic.physionet.org) was created in 2003 as the result of a collaboration between MIT, Philips Medical Systems and the Beth Israel Deaconess Medical Center (BIDMC). The data entered into this database was sourced from medical and surgical patients admitted to all Intensive Care Units at BIDMC. It consists of information from over forty thousand patients, detailed physiological and clinical data, and is de-identified and openly accessible to researchers. Two types of data are present in this database: clinical data derived from EHRs, which are stored in a relational database comprised of approximately 50 tables, and bedside monitor waveforms stored in flat binary files.  The goal of this collaboration is to produce and assess advanced ICU patient monitoring and decision support systems that will ultimately make the process of decision-making in critical care more efficient, quicker and accurate.

PCORnet

PCORnet, the National Patient-Centered Clinical Research Network, is an initiative that began in 2013 with the objective to integrate data from several Clinical Data Research Networks and Patient-Powered Research Networks. It contains 29 networks that will facilitate access to vast amounts of research. It collects data from routine patient visits and data that are shared by individual patients via personal health records or community networks with other patients.

Open NHS

The National Health Services (NHS England) maintains one of the largest repositories in the world containing data related to peoples’ health. Open NHS¹⁰  is an open source database that provides access to information made available to the public by the government or other public bodies. This project was established in order to increase transparency and monitor the efficiency of the British healthcare sector. Patients, healthcare workers and commissioners are given the opportunity to compare the quality of care in various locations of the country by simply accessing the available data in the specially designed database.

Database de-identification

One of the primary steps to building an EHR database is de-identification. Before a database becomes available for use by researchers and applications, it is essential that measures are taken in order to ensure that privacy policies and regulations are followed. For structured data, such as columns of a table, de-identification is based on the categorisation of data and the subsequent deletion or cryptography of those that are flagged as protected. For unstructured data, such as discharge summaries, different techniques of natural language processing are used, from simple regular expressions to complex neural networks, which try to find all information that is protected throughout free text in order to perform deletion or cryptography.

The application of blockchain in Digital health

Blockchain technology is based on the concept of having a decentralised system for data storage, where a copy of the ledger of the performed transactions will be provided to each participant/node. This will make it unfeasible for someone to modify the data without the other participants being informed. Strong centralised entities would benefit from the application of blockchain. The applications of Digital health greatly depend on centralised systems. Therefore, blockchain has the potential to transform Digital health by altering the way data are stored and secured. Various areas have been proposed for its application, including supply chains, drug verification, claims reimbursement, access control and clinical trials.

Medical data has been found to be the most highly valued data by hackers, as recent studies have estimated that a single health record may cost up to 400 USD. This means that keeping the data secure in medical databases is of utmost importance. Blockchain can provide a solution to this issue by ensuring data privacy, integrity, authentication and authorisation. Blockchain data are encrypted and if someone has to delete or make their data useless, they are given that ability by applying a key destruction mechanism, where the key that was originally used for the encryption of the message will be destroyed, or made useless. Afterwards, the data stored in the blockchain will not be accessible to read.

Blockchain is able to fulfil two essential needs regarding data sharing: integrity and non-repudiation. Integrity means that the query and retrieved data cannot be altered, once the retrieval operation has been performed. Non-repudiation means that the knowledge retrieval service does not possess the ability to deny that the specific data have been delivered by the service as a response to a given query at a particular time. Blockchain can be defined as a distributed transaction management system that cannot be corrupted. It can be applied for EHR integration, sharing and access control, preservation and management.

A theoretical blockchain-based query notary service may be comprised of three computational layers:

• a data consumer front-end
• an interface for communicating with biomedical database interfaces, and
• the contract engine, which organisesthe query and returns the retrieved results to the consumer, performs and prepares transactions, and manages contracts and their metadata

Two different schemes may be employed to apply the notary service: the basic scheme and the versioning scheme. The basic scheme applies a query-response ledger by which the user receives a sealed proof verifying that at a specific time a particular query has been placed in a biomedical database, which returned specific results. This scheme may be employed to ensure the integrity and non-repudiation of a query, when a vital biomedical task relies on the specific query. The versioning scheme permits the non-reputable versioning of data retrieved from a dynamically evolving biomedical database at numerous occasions in time, always using the same query. This scheme may be applied to confirm different versions of changing medical evidence as retrieved from a biomedical database with content that is frequently updated.

The incorporation of blockchain technology in pharmaceutical or life science applications has the capacity to decentralise the interface and data sharing, leading to increased efficiency, higher speeds and unlimited scalability. Blockchain renders data immutable, which would be useful in clinical trials for ensuring that clinical data cannot be manipulated by researchers at a later time. It can also be utilised in the process of drug identification, tracing and verification. There are certain risks associated with the implementation of blockchain, such as privacy concerns, off-chain transactions and doubts about this technology due to lack of adoption. Nonetheless, the benefits of blockchain technology far outweigh possible drawbacks and could have a significant role in limiting the methods used for illegal activities.

¹ Source https://intellipaat.com/blog/tutorial/sql-tutorial/sql-commands-cheat-sheet/

² Source https://intellipaat.com/blog/tutorial/sql-tutorial/sql-commands-cheat-sheet/

³ Source SAP SE https://help.sap.com/viewer/eb3777d5495d46c5b2fa773206bbfb46/2.0.01/en-US/d3d1cf20bb5710149b57fd794c827a4e.html

⁴ For more information about supported operating systems for SAP HANA, see SAP Note 2235581 – SAP HANA: https://service.sap.com/sap/support/notes/2235581

⁵ JavaScript Object Notation is an open standard file format as XML and is considered as unstructured data.

⁶ XML is an open standard file format as JSON and is considered as unstructured data.

⁷ Source IBM Support https://www.ibm.com/support/pages/system-requirements-ibm-db2-linux-unix-and-windows#1155S

⁸ Source https://support.oracle.com/knowledge/Oracle%20Database%20Products/1369107_1.html

⁹ Source https://www.guru99.com/free-database-software.html updated on 2021

¹⁰ Open data at the NHS. Available from: http://www.england.nhs.uk/ourwork/tsd/data-info/open-data/

The biogas producing process has already been described in the basic level section. To sum up what already described, in developing countries there has been an increased interest in the development of technologies to produce renewable energy sources.

Main steps towards modern BIOPLASTICS

• Bioplastics are not a real innovation: natural resins were used since ancient times (for example amber, shellac, etc.)
• Starting from 1860, the first plastics deriving from cellulose were released (eg. celluloid, cellophane)
• In the 1940s, Henry Ford made car parts with plastics obtained from soy
• In the ’50s plastics derived from oil spread
• Oil crisis in the 70s: the interest in bioplastics was rediscovered. Currently there is an increase in the demand for bioplastics, mainly due to the pressing environmental problems (depletion of resources, greenhouse effect, waste disposal, etc.). Fig. 5, 6 and 7 give some basic info about bioplastics.

Fig. 5. Bioplastics and European

Plastic and rubber are polymeric materials consisting of monomers. These are mainly produced from petroleum and the originated material is therefore non-renewable. Around 4% of the world’s oil consumption is used as raw material in plastic production, and a similar amount is used as energy in the production process. In addition to petroleum, plastic production requires the use of chemical additives such as plasticizers, flame retardants, heat and UV stabilizers, biocides, pigments, and extenders. Several additives are classified as hazardous according to the EU regulations (carcinogenic, mutagenic, harmful for reproductive health or for aquatic life, or having persistent negative impacts on the environment).

In the ‘60s plastic was considered for the first-time as a concern in sea and ocean pollution and negative health impacts on humans and the environment were starting to be described. Indeed, plastics release toxic chemicals throughout the life cycle of the product.

Plastic recycling emerged as a possible solution. Recycling, however, in not the only solution needed to solve the plastic waste crises that is polluting the environment. Plastic can range from being unrecyclable, recyclable only once or twice, or at a defined number of times but not forever. After this limit, the plastic will end up in a landfill. Furthermore, a lot of plastic consumers do not even allow their plastic to have this long of a life. Renewable plastics, meaning plastics derived from renewable sources and easily biodegradable in the environment, may offer a solution to the problem of bioplastic poisoning.

Fig. 6. Biobased and biodegradable

Fig. 7. Main bioplastics produced

Bio-based is defined in European standard EN 16575 as “derived from biomass”. Biodegradable materials are materials that can be broken down by microorganisms like bacteria or fungi into water, carbon dioxide or methane and biomass. However, biodegradability depends on the environmental conditions: presence of microorganisms, temperature, and availability of oxygen and water. Compostable materials are materials that break down at composting conditions. Industrial composting conditions require elevated temperature (55˚C – 60˚C) combined with a high relative humidity and the presence of oxygen, and they are in fact optimal when compared against other degradation conditions like in soil, surface water and marine water. Compliance with EN 13432 is considered a good measure for compostability of packaging materials. According to this standard, plastic packaging can be called compostable. Some details on the 3 main categories of bioplastics are given below.

Starch-based plastics

75% of all organic material on earth is present in the form of polysaccharides. An important polysaccharide is starch. Plants synthesize and store starch in their structure as an energy reserve. Starch is found in seeds, tubers, or roots of the plants. Sources of starch are corn, wheat, rice, potato, tapioca, pea, and many other plant resources. Most of the starch produced worldwide is derived from corn. Starch is generally extracted from plant resource by wet milling processes. Starch consists of two types of glucose polymers: amylose and amylopectin. Amylose is essentially a linear polymer in which glucose units are predominantly connected through α-D-(l, 4) glucosidic bonds. Amylopectin is a branched polymer, containing periodic branches linked with the backbones through α-D-(l, 6) glucosidic bonds. The content of amylose and amylopectine in starch varies and depends on the starch source.

Fig. 8. Novamont’s starch‐based technology

An important class of plastics is represented by starch‐based plastics. Beginning in the early 1990s, research and technology developments have permitted to complex natural polymers like starch (from maize, potato etc.) with biodegradable macromolecules (polymeric complexing agents) in order to obtain thermoplastic and biodegradable innovative materials on an industrial scale. In particular, Novamont’s starch‐based technology (Fig. 8) employs processing conditions able to almost completely destroy the crystallinity of amylose and amylopectin, in the presence of macromolecules, which are able to form a complex with amylose. They can be of natural or synthetic origin and are biodegradable. The complex formed by amylose with the complexing agent is generally crystalline and it is characterised by a single helix of amylose formed around the complexing agent. Unlike amylose, amylopectin does not interact with the complexing agent and remains in its amorphous state. The source of the starch, i.e. its ratio between amylose and amylopectin, the processing conditions and the nature of the complexing agents allow engineering of various supramolecular structures with very different properties. Over the last few years many successful efforts have been made to increase the amount of renewable raw materials for producing biodegradable polyesters. Novamont is therefore one of the most important players in starch‐based bioplastics. The company is currently working in the development of a biorefinery project consisting of an innovative development model capable of synthesising various chemical intermediates using renewable raw materials cultivated with low input and in marginal areas instead of fossil raw materials.

Polylactic acid plastics

Synthetic biodegradable poly-lactones such as poly-lactic acid (PLA), poly-glycolic acid (PGA), and poly-caprolactone (PCL) are polymers that are degraded by simple hydrolysis of the ester bonds. The hydrolytic products from such degradation process are then transformed into non-toxic subproducts (Fig. 9).

Fig. 9. PLA life cycle

PLA plastics are derived from the fermentation of agricultural by-products such as starch-rich substances like maize, wheat or sugar and corn starch. The process involves conversion of corn, or other carbohydrate sources into glucose followed by fermentation into lactic acid (Fig. 9 and 10).

Fig. 10. PLA production from starch

PLA derived from lactic acid is thermoplastic, biodegradable aliphatic polyester having ample potential for packaging applications. The lactic acid monomers are either directly polycondensed or undergo ring opening polymerization of lactide resulting in formation of PLA pellets. The properties of PLA as packaging material depend on the ratio between the two optical isomers of the lactic acid monomer. When 100% L-PLA monomers are used it results in very high crystallinity and melting point, whereas 90/10% D/L copolymers fulfils the requirements of bulk packaging. PLA is the first biobased polymer commercialized on a large scale and can be shaped into injection moulded objects, films and coatings. PLA has replaced high-density polyethylene, low-density polyethylene (LDPE), polyethylene terephthalate and PS as packaging material.

The main properties of PLA are: i) the mechanical resistance and heat sensitivity are similar to traditional plastics; ii) hardness, stiffness and degree of elasticity are similar to PET, iii) it can contain fats, oils, alcohol and aliphatic molecules, iv) scarce resistance to acids and bases is but good resistance to UV radiation, v) it can be printed and dyed, vi) it can be transformed into goods through standard machines used for traditional plastics, vii) the post-use phase may involve composting in industrial plants.

Polyhydroxyalcanoates

Polyhydroxyalkanotes (PHAs) are bio-degradable polymers that are accumulated by some bacteria as storage compound in form of intracellular granules. PHA is one of the biopolymers that can effectively replace the conventional petrochemical plastics with their material properties that parallel them. Even then, their production at large scale is still limited by its high production cost compared with conventional fossil-fuel based plastics as the PHA price, depending on polymer composition, ranges from 2.2 to 5.0 €/kg that is at least three times higher than the major petrochemical based polymers which cost less than 1.0 €/kg (calculations made in 2016).

In the majority of companies producing PHAs, mostly pure cultures are used. The problem with the use of pure cultures is the requisites for sterility, refined substrates if plant-based feedstocks are not used, thus limiting the process of commercialisation. All these issues shall be overcome using Mixed Microbial Cultures (MMCs): this combines the transformation of waste into value added product production. Biological treatment of wastewater and sludge management for recovering carbon from wastewater as PHAs is a route to transform end-of-pipe environmental protection infrastructure into bio-refineries. Integration strategies for MMC PHA production within wastewater treatment processes have been proposed for industrial process wastewater and municipal wastewater treatment.

One of the best characterized members of the PHA family is polyhydroxybutirate (PHB), produced by microorganisms that store it inside the cell cytoplasm. In 1926, a microbial production of linear polyester of D (-)-3-hydroxybutyric acid as intracellular granules, which occurred in both gram-positive and gram-negative bacteria under a starvation conditions, was first discovered (Fig. 11).

Fig. 11. Polyhydroxybutirate

Cost is the major drawback of PHB production during industrialization. Industrial production of PHB is costly than that of petroplastics. Large quantities PHB production is estimated about 4.4 USD/kg, i.e. far more expensive than polypropylene production cost, which is close to 1 USD/kg. The financial difficulties are undoubtedly related to production costs, both upstream and downstream processes. Approximately, 40% and 50% of overall production cost of PHB have been assigned to crude material and separation/purifcation systems, respectively. In bioextraction techniques, genetic engineering is the most commonly used to introduce microorganisms, and they are capable of effectively extracting PHB from PHB accumulating cells. There are several approaches that have been investigated including bacteriophage-mediated lysis system and predatory bacteria, which are better than the conventional extraction approaches that produce environmentally harmful solvents, with higher cost of degradation. Thus, due to the non-environmental and non-economical friendly properties of conventional extraction methods, more attention is given to bioextraction systems.

This unit is basically focused on the technologies that allow the study of the microbiota in soil or complex matrixes. The main technologies are depicted below (Fig. 12).

Fig. 12: Techniques to study the microbiome complexity

The culturomic approach is well described in the video that has been produced within Digit-Biotech. This “classical method”, provide for the identification of microorganisms through the isolation of pure cultures, followed by tests that analyze some morpho-physiological and biochemical characteristics. These analyzes are often not sufficient for the identification of most species of microorganisms and moreover are limited to cultivable species which represent a very small percentage of all species found in nature. These tests also have the serious limitation of requiring considerable time consuming. However, they have the great advantage of the obtainment through the isolation approach of target microorganisms that can be used in the bioremediation approach.

Over the past few decades, research in the field of microbiology environmental have shown that microbial communities play a functional role of control of ecosystems that is not attributable to individual species but to the communities themselves as “functional units”. This functional activity of microbial communities is, in many cases, responsible for important processes for humans, including the biodegradation of original waste in wastewater treatment plants and landfills, composting and, in general, all the processes in which chemical transformations of the substances produced by the activities take place. Denaturing Gradient Gel Electrophoresis (DGGE), real time PCR (or quantitative PCR), and whole genome approach (high-throughput sequencing and shotgun sequencing) are the main technologies used for the study of microbial populations in the environment.

DGGE: it is a electrophoretic separation technique used for the separation and analysis of DNA fragments that differ in the nucleotide sequence also of a single base pair. In classical electrophoresis conducted on agarose or acrylamide gel, DNA fragments are separated on the basis of molecular weight; the running speed decreases parallel to the increase in length of the fragment. On the contrary, in the DGGE, fragments of DNA of equal molecular weight are separated according to the denaturation pattern. The presence of heat or chemical denaturants allows the denaturation of the two filaments constituents of a double-stranded DNA (dsDNA) molecule. Temperature and concentration of denaturant to which the separation of the two filaments occurs strongly depend on the sequence of the fragment itself. In particular, the determining factors are: quantity of bonds hydrogen that are established between complementary bases and type of interactions that are established between bases adjacent on the same strand (stacking interaction). A DNA molecule therefore has domains with characteristic melting temperatures or Tm, determined by nucleotide sequence. DNA fragments almost identical in molecular weight, but that they also differ in a single nucleotide, they can be characterized by Tm and melting domains different from each other. The DGGE analysis is conducted on polyacrylamide gel containing a gradient denaturing in such a way that the dsDNA is subject, during the run, to an increase in denaturation conditions with consequent separation at the melting domains. In the upper part of the gel, where there are mild denaturation conditions, the melting domains at lower Tm begin to partially denature, creating branched molecules with less mobility. The increase in denaturation conditions along the polyacrylamide gel can determine the total dissociation of partially denatured fragments in single-stranded DNA (ssDNA). Experimentally, the complete dissociation of the two dsDNA strands is hindered by introducing, at the end of each filament, domains characterized by high contained in G + C and high Tm. G + C-rich regions are artificially created at one end of the dsDNA by means of incorporation of a GC-clamp during amplification reactions. The incorporation of the GC-clamp is made possible by the use of primers characterized by a sequence of about 30-40 GC at the 5 ‘end. The presence of the GC-clamp of the same sequence at the extremity of each molecule causes the differences between the stroke profiles of the analyzed fragments to be mainly determined by variations in the sequence of low melting domains. Since Tm is determined by the nucleotide sequence, the presence of a single mutation is capable of generating a different denaturation profile and, consequently, a different electrophoretic run. Hence the recurrence of polymorphisms in highly conserved genes can be analyzed by DGGE and can provide useful information to characterize the structure of microbial communities. In fact, with denaturing gradient gel electrophoresis an electrophoretic profile formed by a series of bands is obtained in which, as a first approximation, the number of bands is proportional to the number of species present and the position of each band is different for each species. The DGGE technique therefore provides a simple approach to obtaining microbial community profiles that can be used to identify spatial and temporal differences in the community structure or to monitor changes in structure that occur in response to environmental disturbances.

Real time PCR: It is a technique that allows to amplify and at the same time quantify a target DNA sequence. It involves the use of fluorescent dyes, such as Sybr Green that intercalate in the minor sulcus of the DNA double strand, or probes with specific sequences, consisting of oligonucleotides labeled with fluorescent agents. The emitted fluorescence is constantly measured and provides “real time” information on the amount of amplicon produced. From an amplification reaction a graph with a sigmoidal curve is obtained; this will start as soon as possible the greater the quantity of starting DNA and will continue to grow with an exponential trend until it reaches a maximum value (plateau), in which the reaction will slow down due to the exhaustion of the substrates.

In studying a Real Time PCR graph, three parameters are established:

– the fluorescence baseline or baseline region;

– the threshold line, parallel to the base line;

– the threshold cycle or CT, specific for each sample, identifies the value of the PCR cycle in which the exponential phase curve intersects the threshold line.

Most Real-Time PCR instruments are programmed to read the wavelengths of the SYBR Green emission and excitation spectrum (respectively 495nm and 537nm). This dye is very sensitive to light, it binds only to double-stranded DNA and therefore only to the newly synthesized amplicon. The samples are quantified on the basis of calibration curves obtained through the use of known quantities of 16 S rDNA gene copies. The comparison between the signal emitted by the unknown sample with the fluorescence values used for the construction of the calibration curve allows the quantification of a specific microbial species. In addition to the quantitative measurement of target bacteria, intercalators such as SYBR Green allow to distinguish amplicons of different lengths and to detect non-specific amplifications that may be present.

Next Generation Sequencing: The peculiarity of this technology introduced in 2006 consists not only in the ability to sequence a single DNA fragment at a time, extending this process to millions of fragments at the same time, but also in the ability to sequence DNA fragments in both directions.

The first step involves single-stranded DNA fragments, at the ends of which univocal sequences, called “index”, are loaded onto a flow of cells where they are captured on a surface containing “oligonucleotides still” complementary to the indexes, on which they are immobilized for the preparation of the libraries. The hybridization between the latter and the DNA fragments occurs through heating and cooling processes, followed by incubation with specific reagents and an isothermal polymerase. Through a “bridged” amplification each fragment is amplified distinctly from the others, creating a cluster of clones. When the cluster generation is complete, the generated models, after appropriate denaturation, are ready for actual sequencing.

Illumina uses a technology based on chain terminating fluorescent nucleotides with an OH at 3 ‘; this ensures that a single base per cycle is incorporated. An imaging step follows to identify the nucleotide incorporated in each cluster and a chemical step to remove the fluorescent group and terminal OH to allow the incorporation of another base in the next cycle.

At the end of the sequencing, which takes about 4 days, the sequence of each cluster is subjected to selection processes (trimming) to eliminate the low-quality products. During the data analysis the fragments of various lengths are aligned and superimposed, in this way it is possible to identify the sequence of the starting filament. In a standard procedure, at least 40-50 million sequences are analysed.

The shotgun sequencing is the sequence of all the genomes present in a complex matrix, such as a soil sample. Shotgun sequencing is therefore the most efficient way to sequence a large piece of DNA. For this, the starting DNA is broken up randomly into many smaller pieces, sort of in a shotgun fashion, with each of those pieces then sequenced individually. The resulting sequence reads generated from the different pieces are then analyzed by a computer program, looking for stretches of sequence from different reads that are identical with one another. When identical regions are identified, they are overlapped with one another, allowing the two sequence reads to be stitched together. This computer process is repeated over and over and over again, eventually yielding the complete sequence of the starting piece of DNA. The initial random fragmenting and reading of the DNA gave this approach the name “shotgun sequencing”.

Numerous biotic and abiotic stresses, such as the massive use of pesticides in agriculture and climate change, are compromising the survival of pollinating insects, with potentially harmful consequences on both agroecosystems and natural systems. In fact, bees are responsible for the pollination of 84% of cultivated plant species, 35% of which are of global importance and 78% of wild ones. Suffice it to say that 70% of seed crops alone (such as carrots, onions, garlic, etc.) are strictly dependent on insect pollination, as well as 80% of the 264 crop species of interest in Europe. From this, it follows that the activity of pollinating insects, including bees, plays an essential role at an economic level whose monetary estimate is about € 15 billion / year in Europe alone, while at worldwide the estimate grows to 153 billion €/year.

In addition to an incalculable value for the maintenance of biodiversity and balances present in the various ecosystems, then, bees supply honey, beeswax, propolis, pollen and royal jelly: in Europe, the data collected in 2010 showed a production of about 220 000 tons of honey with prices ranging from 1.50 to 40 €/kg depending on the area of ​​origin. Or, in Australia the production of honey and beeswax annually hovers around a commercial value of $ 90 million, underlining again the importance that the beekeeping sector plays in the panorama. world economy. Honeybee colonies have declined rapidly from 6 million in the 1940s to about 2.6 million today. High annual honeybee colony loss is still observed and has become the norm for beekeepers. Gut health plays a significant role in innate host immune response and adaptability to the multitude of stressors honeybees face today.

Broods affected by “Colony Collapse Disorder” (CCD), or “Hive Depopulation Syndrome” also showed significant signs of imbalance. The causes of this syndrome are not yet clear, but it is thought that they may be attributable to changes in environmental factors, malnutrition, the presence of pathogens and the massive use of insecticides. The symptomatology sees the presence of broods that abandon their larvae despite the presence of the queen, and lack of appetite for pollen and nectar stocks that are not consumed immediately (Fig. 13).

Fig. 13. Insights on Colony Collapse Disorder

One of the possible causes of this die-off may be related to gut microbiota dysbiosis, as microbial alteration in terms of quantity and composition. With this term we indicate the phenomenon that negatively affects the beneficial functions of the microbiota and that are associated with specific metabolic imbalances. In fact, these deficiencies could create serious problems on the development of young adults by affecting their ability to develop resistance genes, including those for the synthesis of vitellogenin, and by inhibiting the functions of the immune system, given the evidence that the same microbiota promotes its effectiveness (Fig. 14).

Fig. 14. Consequences of altered gut microbial compositions in bees

Few years ago, we tried to understand which factors are able to destabilize the microbiota, arriving at the conclusion that dysbiosis is caused by both biotic and abiotic factors. Considering biotic stresses, it has been seen that diet, the presence of specific pathogens and disorders (e.g., CCD) and adverse environmental conditions play a fundamental role. The lack of nutrients has a destructive impact on the normal development of the intestinal microbial flora, the consequence of which is to increase honeybee’s mortality, as well as increase the susceptibility to diseases and pathogens. Furthermore, the anomalous temperatures induce a state of stress in the hosts such as to have dramatic repercussions on the symbionts.

Considering abiotic stressors, the damage is almost entirely attributable to the use of insecticides, fungicides, acaricides and antibiotics. The bees, in fact, during foraging operations risk to ingest indirectly and to encounter the active ingredients, both on the main crops treated and on the neighboring ones subjected to drift. This could cause serious problems and imbalances in metabolism and immune defenses: in fact, there is the possibility that exposure to certain substances interferes with the ability of bees to regulate their microbial gut population.

For those reasons, one of the most innovative future prospect aim to understand the in-depth relationship between microorganisms and honeybees, in order to improve their dramatic lifespan and conditions.

Gut disbiosis: an example

Given the growing interest that public opinion is showing towards this product, the first objective analysis falls on the effect of Glyphosate (N-phosphonomethyl-glycine). It is a non-selective post-emergence systemic herbicide, therefore a total herbicide. Its mechanism of action interrupts the metabolic pathway responsible for the synthesis of phenylalanine, tyrosine and tryptophan, inhibiting the synthesis of 3-phosphoshikimate-1-carboxyvinyltransferase (EPSP synthase). This herbicide has always been seen as one of the least toxic products for animals, as they lack this metabolic pathway. Despite this, it has been shown that it can affect non-target organisms showing highly toxic effects towards earthworms, microalgae, aquatic bacteria, rhizosphere, and endophytes. Affecting the bacteria, then, it should be emphasized that the effects were also detected in intestinal microorganisms and symbionts of the fauna adjacent to agricultural areas, including bees.

Specifically, Motta et al. (2018) conducted a study aimed at characterizing the microbiota of bees exposed to Glyphosate, concluding that the absolute abundance of S. alvi, G. apicola, Lactobacillus sp. and Bifidobacterium sp. (Fig. 15)

Fig. 15. Analyses on the bee gut microbiota

has undergone a significant decrease. The product compromised the bacterial flora by stopping their growth without, however, directly killing them; it was therefore hypothesized that the effect fell on cell division during the early days of colonization. The bees that encountered the herbicide in the field, in fact, would have carried the active ingredient inside the hive which, being very stable and insoluble in water, would have been able to remain on the surfaces for a long time. Similarly, even in the field, persistence means that contamination can last for a long time. Inside the hive, therefore, the diffusion by trophallaxis and contact with other bees means that the product reaches the young larvae fed by adults, irreparably altering the development of beneficial symbiont species.

How is the microbiota acquired?

Fig. 16. The growth cycle of a bee

Natural bacteria picked up by honeybees from flowers while collecting nectar and pollen reside predominantly in honeybee midgut and hindgut. Gut bacteria naturally found in honeybees are dynamic. During development of the larvae (Fig. 16), bacterial population fluctuates. Larvae receive some bacteria from the nurse bees feeding them. During pupation, the gut lining is shed, and the gut of a newly emerging adult honeybee is sterile. The gut is quickly repopulated with characteristic microbiota. How does this happen? Main pathways are oral trophallaxis, interaction with hive material, and fecal-oral transmission. In particular, the characteristic microbiota of adult bees begins to develop about four days after the flicker.

Although the factors that allowed the evolution of the microbiota for every living being are still unknown, it is proven that social bees possess a distinctive microflora depending on the family they belong to. For example, it has been seen that analyzing the microbiota of different genera of eusocial corbiculate Apoidea such as Bombus spp., Megachile spp. and Apis spp., the main bacterial genera were recurrent (Snodgrassella spp., Gilliamella spp., Bifidobacterium spp. and Lactobacillus spp.) but the species varied in relation to the insect species. Hence the hypothesis that sees the microbiota as the result of a dynamic co-evolution between microorganisms and hosts, dependent on the environment and on the genotypic variations to which the species have been subjected over the centuries, whose richness is also correlated with the size of individual bees and entire colonies. In fact, the establishment of a species-specific microbial flora is the result of a long selection in which the optimal beneficial ratios have been established both for the microorganisms and for the hosts.

Who and where are they?

It has been estimated that within the intestines of adult worker bees there are about 1 billion bacterial cells, 95% of which are located, specifically, in the hindgut (Fig. 17). Here, a specific differentiation between ileus and rectum was noted; in the first three species of Proteobacteria such as G. apicola, F. perrara and S. alvi which form a dense biofilm in correspondence with the Malpighian tubes and which continues along the length of the ileum wall. In the rectum, however, a dense bacterial community prevails formed by three classes of Gram positive, such as Firmicutes (Firm-4, Firm- 5) and Bifidobacteria. As for the midgut, it has been seen that there are mainly Lactobacillus spp. and Acetobacteraceae, that is, those taxa that are also found in pollen, nectar and more generally within the hive. It can therefore be said that a pre-adapted microbiota does not exist in the midgut and that it varies in relation to the environment and the individual’s eating habits. In quantitative terms, then, here there is a much less abundant flora than in the rectum. The midgut also contains few bacteria, and those presents are more concentrated in the pro-ventricular area adjacent to the hindgut.

Fig. 17. The growth cycle of a bee

What are the gut microbiota functions?

In the last few years, the scientific community has begun to take an increasing interest in the role that the microbiota plays in the wellbeing of honeybees (Fig. 18). Numerous studies and research have shown that interactions with the host have supportive effects both at a metabolic and nutritional level and in terms of immune response to pathogens. As for food support, a balanced bacterial flora is necessary for a correct assimilation of nutrients as, thanks to its enzymatic activity, it participates in the degradation of complex sugars. In addition to being responsible for the presence of cellulases, hemicellulases and ligninolytic enzymes in the intestine useful for the digestion process of pollen grains, the richness of species is such as to allow the coexistence of different sugar catalysis pathways (especially for Gammaproteobacteria, Firmicutes and Bifidobacteriaceae). Indeed, it has been estimated that 91% of the protein transcripts linked to the digestion of plant macromolecules and to the fermentation phenomena of monomeric subunits are produced by bacteria. Another concrete example concerns pectin-lyases capable of degrading the pectins present in the cells of the wall of pollen grains. The latter is also an excellent indicator of the high genetic variability and adaptability within the same species of microorganisms. In fact, it has been seen that only some strains of G. apicola possess them while others are completely devoid of them. The importance of a greater digestive capacity and, consequently, the ability to metabolize nutrients that could not be demolished, has been demonstrated in various studies. Zheng et al. (2017), for example, by comparing bees with a normal microbiota and others without any type of intestinal flora, they highlighted appreciable physiological differences. In the former, the symbionts positively influenced the size of the intestine, the weight of individuals, the values ​​of vitellogenin and insulin and the sensitivity to sugars. These findings then suggested that the microbiota could influence the appetite and growth of the bees’ body through the increase of signals related to the presence of insulin.

In addition to the hydrolysis of complex carbohydrates, intestinal microorganisms produce useful metabolic substrates, such as vitamin B and other and short chains of fatty acids. For example, it has been seen that the genera Lactobacillus sp. and Bifidobacterium sp. are involved in the processes of fermentation of pollen and nectar so that they can be considered responsible for the vitaminic value of honey. The phenomenon of symbiosis with the host goes beyond nutritional and metabolic support: the microbiota plays an important role in supporting the immune system. In fact, in the first place, the bacteria could directly stimulate the production of the bee’s own defense molecules. Following the contact between the epithelial surface and the peptidoglycan (major component of the cell wall of Gram-positive bacteria), the immune system could activate the genes to produce 6 antimicrobial peptides such as: abaecin, hymenoptaecin, apidicin, defensin-1 and defensin-2. The production of these compounds, then, is accentuated by the alterations of the microbial membranes themselves and can also be induced by exposure to some pathogenic and non-pathogenic microorganisms. For example, Frischella perrara, a symbiont that colonizes the ileum region in the hindgut, above all stimulates the production of apidicin. Secondly, the microbiota may be directly responsible to produce antimicrobial compounds, which, among other things, is confirmed by numerous studies. Saraiva et al. (2015), for example, documented the presence of numerous genes involved in the biosynthesis of streptomycin and of secondary metabolites expressed by symbionts and which may play a role in maintaining the microbiota.

Fig. 18. Functions of the bee gut

What can we do?

From our and general experience in humans and animals, biotic and abiotic stresses could negatively affect the composition of the gut microbiota and therefore induce specific changes in the microorganism activities at gut level.

We must ask ourselves if any kind of microbiota modulation, by the administration of selected strains, could restore this perturbation, reduce bee mortality and/or improve honeybee health.

Probiotics are “live microorganisms that, when administered in adequate quantities, bring a benefit to the health of the host, excluding references to biotherapeutic agents and beneficial microorganisms not used in food” (FAO / WHO, 2001). Their administration, then, must not be associated with negative effects on organisms and the environment. The mode of action of these microorganisms can be summarized in the following functions:

• PROTECTIVE FUNCTION: dislocation of pathogens, competition for nutrients, competition with receptors and production of antimicrobial molecules (eg bacteriocins, organic acids …);
• STRUCTURAL FUNCTION: barrier effect, biofilm on the intestinal hair wall, development of the immune system;
• METABOLIC FUNCTION: differentiation and proliferation of intestinal epithelial cells, catalysis of carcinogenic substances present in the diet, synthesis of vitamins, fermentation of non-digestible sugars, ionic absorption, and energy saving.

However, it seems that the main mechanism of action of probiotics is the stimulation of the immune system: following cohesion with the intestinal wall, they are able to stimulate a series of cascade signals that activate the synthesis of antimicrobial peptides. In practice, they are able to carry out those tasks described previously that the bee’s microbiota naturally performs, proving to be a hypothetical optimal aid in safeguarding and optimizing it, as well as improving the bee’s life prospects.

As with human and animal nutrition, the main bacteria considered capable of these benefits are Lactobacillus spp., Bifidobacterium spp., Bacillus spp.

In conclusion, the use of probiotics has recently begun to be evaluated also within the hive itself. In fact, although bees prefer to consume fresh pollen, under certain conditions, such as seasonality, they need to supply themselves with the stored reserves. The humid environment (50-60% RH) that is created following the collection of pollen increases the risk of uncontrolled bacterial and, above all, fungal growth. There is a clear need to preserve the stocks inside the hive to avoid infections that could lead to fatal outcomes, such as calcified larvae due to Ascosphaera apis, or intestinal infections due to Nosema spp.