The following points highlight the four main applications of biotechnology in environment. The applications are: 1. Waste Treatment 2. Biodegradation 3. Microorganisms in Pollution Control 4. Biomass Energy Production.
Application # 1. Waste Treatment:
The overall production of methane from organic wastes is a complex fermentation involving a number of groups of microorganisms (Methanogens, member of Archaebacteria). They utilize the anaerobic environment and organically enriched sediments.
The aerobic waste treatment requires a large population of actively metabolizing microorganisms such as Pseudomonas, Alcaligenes, Achromobacter and Brevibacterium, able to degrade both colloidal and soluble organics with high rate of conversion of CO2 and water.
Due to anaerobic decomposition of organic waste material, the most important component produced is methane, which can be easily collected and used as biogas fuel. Other than methane, some other products are produced due to the activity of facultative anaerobes.
The nitrogenous waste materials are treated both aerobically and anaerobically alternatively. The degradation of nitrogenous compounds gives ammonia, which is then converted to nitrate by nitrifying bacteria. Then by the action of denitrifying bacteria in anaerobic environment releases N2 gas in the atmosphere.
Application # 2. Biodegradation:
It is the process by which materials such as oil spill, herbicides, pesticides, etc. are degraded by the action of microbial system. Organic compounds which are naturally occurring (biogenic) are biodegradable while man-made (xenobiotic) compounds may be biodegradable, persistent or recalcitrant.
Genes coding for some enzymes essential for the biodegradation of a number of organic compounds are plasmid borne and organisms have been constructed to degrade difficult waste. A strain of Pseudomonas putida is constructed to contain plasmids coding for the breakdown of octane, xylene, metaxylene and camphor. This organism is claimed to be useful for cleansing of oil spills.
Application # 3. Microorganisms in Pollution Control:
Microbial strains can be isolated in order to control various forms of chemical pollution such as biocides, detergents, plastic materials and hydrocarbons. The bacteria belonging to the genus Pseudomonas have oxidoreduction or hydroxylation enzymes capable of degrading a large number of hydrocarbon molecules or aromatic compounds that are often highly toxic.
Genetic recombination techniques should make it possible to achieve such a result that a single microbial strain will be capable of decomposing and assimilating numerous compounds, most often non-biodegradable (xenobiotic), produced by the chemical industry.
Application # 4. Biomass Energy Production:
Environmental biotechnology also deals with various sources of energy. Biomass is the Jiving matter or its residues, a perpetual or renewable source of energy. Ethanol is formed from various sources, such as cassava, cereals, potato, sugarcane, pineapple, sugar beet, etc.
It is a solvent and also a substrate for the synthesis of many other components and dyes. Biogas formation and methanogenesis are although ancient forms, today they are in great demand. Methane fermentation is widely practiced and is one of the easily available sources of energy.
Agricultural wastes and farmyard wastes are efficiently used for this purpose. Production of biogas in rural areas has been a priority in the energy policy of India.