What Is Environmental Biotechnology All About?
Heavy metals in soil and drinking water, landfill leachate, dirty laundry – why not get nature to help us in our efforts to clean soil, laundry and water? Biotechnologists are increasingly learning how to apply the knowledge about biological metabolic processes in the field of environmental protection, including waste management and environmental rehabilitation. Environmental biotechnology is a field with great potential. In future, bacteria and other microorganisms will most likely also contribute to sustainability and cost efficiency in other areas, including the cosmetics and detergent industry as well as in the production of fine and bulk chemicals.
Environmental biotechnology is a system of scientific and engineering knowledge related to the use of microorganisms and their products in the prevention of environmental pollution through biotreatment of solid, liquid, and gaseous wastes, bioremediation of polluted environments, and biomonitoring of environment and treatment processes.
The advantages of biotechnological treatment of wastes are as follows: biodegradation or detoxication of a wide spectrum of hazardous substances by natural microorganisms; availability of a wide range of biotechnological methods for complete destruction of hazardous wastes; and diversity of the conditions suitable for biodegradation.
The main considerations for application of biotechnology in waste treatment are technically and economically reasonable rate of biodegradability or detoxication of substances during biotechnological treatment, big volume of treated wastes, and ability of natural microorganisms to degrade substances. Type of biotreatment is based on physiological type of applied microorganisms, such as fermenting anaerobic, anaerobically respiring (anoxic), microaerophilic, and aerobically respiring microorganisms. All types of biotechnological treatment of wastes can be enhanced using optimal environmental factors, better availability of contaminants and nutrients, or addition of selected strain(s) biomass.
Bioaugmentation can accelerate start-up or biotreatment process in case microorganisms, which are necessary for hazardous waste treatment, are absent or their concentration is low in the waste; if the rate of bioremediation performed by indigenous microorganisms is not sufficient to achieve the treatment goal within the prescribed duration; when it is necessary to direct the biodegradation to the best pathway of many possible pathways; and to prevent growth and dispersion in waste treatment system of unwanted or nondetermined microbial strain which may be pathogenic or opportunistic one.
Biosensors are essential tools in biomonitoring of environment and treatment processes. Combinations of biosensors in array can be used to measure concentration or toxicity of a set of hazardous substances. Microarrays for simultaneous qualitative or quantitative detection of different microorganisms or specific genes in the environmental sample are also useful in the monitoring of environment.
There are many examples of areas where environmental biotechnology can be applied. By focusing on selected examples, the current dossier shows Baden-Württemberg at the forefront of exploitation and investigation of the potential of environmental biotechnology. Scientists from Tübingen have developed a method involving mineral-forming bacteria that degrade arsenic in water. Biotechnology has also proven useful for the remediation of contaminated soils.
The company IBL Umwelt- und Biotechnik GmbH in Heidelberg has developed an in situ technology where naturally occurring soil microrganisms can be activated in several steps, leading to the degradation of mixtures of toxic substances such as benzene, toluene and aliphatic and chlorinated hydrocarbons.
Mosses that grow on trees are excellent indicators for airborne pollution. © Reski
Biosensors used for the detection of harmful substances in water, air and soil are the key tools of environmental biotechnology. Researchers are developing systems based on microorganisms of enzymes that can help indicate environmental toxins. Since 1996, the European Union has required that their member states continually monitor air pollution.
This requirement was tightened in 2008 with an EU directive to monitor not only nitrogen oxides and sulphur oxides but also airborne heavy metals like cadmium, lead and nickel. This is hard to achieve with existing technologies as they are either imprecise or very expensive. A group of researchers led by Prof. Dr. Ralf Reski is part of the MOSSCLONE consortium, which receives funding of 3.5 million euros for three years from the EU under its Eco-innovation initiative, whose objective is to develop a novel, precise and inexpensive method to monitor air contamination, especially by heavy metals. The innovative method is based on the use of mosses, which are well suited as bio-indicators for airborne pollution.
Saving raw materials and resources is another form of environmental protection. Growing interest in and use of renewable fuels suggests that it is likely that the importance of biotechnology in this area will increase significantly over the next few years, for example with regard to the production of bulk chemicals, which up until now have been produced using petrochemical manufacturing methods.
Environmental biotechnology in particular is the application of processes for the protection and restoration of the quality of the environment.
Environmental biotechnology can be used to detect, prevent and remediate the emission of pollutants into the environment in a number of ways.
Solid, liquid and gaseous wastes can be modified, either by recycling to make new products, or by purifying so that the end product is less harmful to the environment. Replacing chemical materials and processes with biological technologies can reduce environmental damage.
In this way environmental biotechnology can make a significant contribution to sustainable development. Environmental Biotechnology is one of today’s fastest growing and most practically useful scientific fields. Research into the genetics, biochemistry and physiology of exploitable microorganisms is rapidly being translated into commercially available technologies for reversing and preventing further deterioration of the earth’s environment.
The aim of environmental biotechnology is to prevent, arrest and reverse environmental degradation through the appropriate use of biotechnology in combination with other technologies, while supporting safety procedures as a primary component of the programme.
Specific Objectives are:
1. To adopt production processes that make optimal use of natural resources, by recycling biomass, recovering energy and minimizing waste generation.
2. To promote the use of biotechnological techniques with emphasis on bioremediation of land and water, waste treatment, soil conservation, reforestation, afforestation and land rehabilitation.
3. To apply biotechnological processes and their products to protect environmental integrity with a view to long-term ecological security.
Use of biotechnology to treat pollution problems is not a new idea. Communities have depended on complex populations of naturally occurring microbes for sewage treatment for over a century. Every living organism—animals, plants, bacteria and so forth—ingests nutrients to live and produces a waste as a by-product. Different organisms need different types of nutrients.
Certain bacteria thrive on the chemical components of waste products. Some microorganisms feed on materials toxic to others. Research related environmental biotechnology is vital in developing effective solutions for mitigating, preventing and reversing environmental damage with the help of these living forms. Growing concern about public health and the deteriorating quality of the environment has prompted the development of a range of new, rapid analytical devices for the detection of hazardous compounds in air, water and land. Recombinant DNA technology has provided the possibilities for the prevention of pollution and holds a promise for a further development of bioremediation.
Applications of Environmental Biotechnology:
Environmental protection is an integral component of sustainable development. The environment is threatened every day by the activities of man. With the continued increase in the use of chemicals, energy and non-renewable resources by an expanding global population, associated environmental problems are also increasing. Despite escalating efforts to prevent waste accumulation and to promote recycling, the amount of environmental damage caused by over-consumption, the quantities of waste generated and the degree of unsustainable land use appear likely to continue growing.
The remedy can be achieved, to some extent, by the application of environmental biotechnology techniques, which use living organisms in hazardous waste treatment and pollution control. Environmental biotechnology includes a broad range of applications such as bioremediation, prevention, detection and monitoring, genetic engineering for sustainable development and better quality of living.
Bioremediation refers to the productive use of microorganisms to remove or detoxify pollutants, usually as contaminants of soils, water or sediments that otherwise intimidate human health. Bio treatment, bio reclamation and bio restoration are the other terminologies for bioremediation. Bioremediation is not a new practice. Microorganisms have been used for many years to remove organic matter and toxic chemicals from domestic and manufacturing waste discharge.
However, the focus in environmental biotechnology for fighting different pollution is on bioremediation. The vast majority of bioremediation applications use naturally occurring microorganisms to identify and filter toxic waste before it is introduced into the environment or to clean up existing pollution problems.
Some more advanced systems using genetically modified microorganisms are being tested in waste treatment and pollution control to remove difficult-to-degrade materials. Bioremediation can be performed in situ or in specialized reactors (ex situ). Bioremediation by microorganisms need appropriate environment for the clean up of the polluted site.
The relative importance of biotechnology is increasing as scientific knowledge and methods improve. Its lower requirements for energy and chemicals, combined with lower production of minor wastes, make it an increasingly desirable alternative to more traditional chemical and physical methods of remediation. Applications of bioremediation for maintenance of environment are several. In this chapter a few are dealt with as handling of waste water and industrial effluents, soil and land treatment, air and waste gases management.
Waste Water and Industrial Effluents:
Water pollution is a serious problem in many countries of the world. Rapid industrialisation and urbanization have generated large quantities of waste water that resulted in deterioration of surface water resources and ground water reserves. Biological, organic and inorganic pollutants contaminate the water bodies.
In many cases, these sources have been rendered unsafe for human consumption as well as for other activities such as irrigation and industrial needs. This illustrates that degraded water quality can, in effect, contribute to water scarcity as it limits its availability for both human use and the ecosystem. Treatment of the waste water before disposal is of urgent concern worldwide.
In sewage treatment plants microorganisms are used to remove the more common pollutants from waste water before it is discharged into rivers or the sea. Increasing industrial and agricultural pollution has led to a greater need for processes that remove specific pollutants such as nitrogen and phosphorus compounds, heavy metals and chlorinated compounds.
Methods include aerobic, anaerobic and physico-chemical processes in fixed-bed filters and in bioreactors in which the materials and microbes are held in suspension. Sewage and other waste waters would, if left untreated, undergo self-purification but the process requires long exposure periods. To speed up this process bioremediation measures are used.