Pollutant-degrading microorganisms

Microbiological conversion processes, typically using microorganisms, which degrade the pollutants to compounds which are less polluting. There are two types of microbiological conversion processes anaerobic processes and aerobic processes. 

Dwyer, D. F. (1994). Behavior of pollutant-degrading microorganisms in aquifers predictions for genetically engineered organisms. Environmental Science and Technology, 28, 1134-8. 

The significance of microorganisms in degradation of man-made chemicals (xenobiotics) including plastics, solvents, lubricants, detergents, pesticides and other pollutants in the environment has been reviewed by several authors (e.g., refs. [68, 71-74]). 

As noted, TSCA coverage extends to chemical substances and mixtures used in a broad range of industrial, commercial and consumer applications. Some examples of the types of microbial products that would be subject to TSCA are microorganisms used to produce pesticides and other commercial chemicals, to convert biomass to energy, for pollutant degradation and enhanced oil recovery, in metal extraction and concentration, and in certain non-food agriculture applications, such as nitrogen fixation. 

Environmental Fate. A portion of releases of toluene to land and water will evaporate. Toluene may also be degraded by microorganisms. Once volatilized, toluene in the lower atmosphere will react with other atmospheric components contributing to the formation of ground-level ozone and other air pollutants. 

Environmental Fate. Most of the MEK released to the environment will end up in the atmosphere. MEK can contribute to the formation of air pollutants in the lower atmosphere. It can be degraded by microorganisms living in water and soil. 

The refractory nature of some pollutants, notably, persistent polyhalogenated compounds, has raised problems of bioremediation of contaminated sites (e.g., sediments and dumping sites). There has been interest in the identification, or the production by genetic manipulation, of strains of microorganisms that can metabolically degrade recalcitrant molecules. For example, there are bacterial strains that can reductively dechlorinate PCBs under anaerobic conditions. 

A further application of the manipulation of microbial activity in the rhizo-sphere is their potential to remediate contaminated land. Bioremediation involves the u.se of microorganisms that break down contaminants. Radwan et al. (255) found that the soil associated with the roots of plants grown in soil heavily contaminated with oil in Kuwait was free of oil residues, presumably as a result of the ability of the resident rhizosphere microflora to degrade hydrocarbons. The use of plants as a means to accumulate pollutants such as heavy metals (256,257) to degrade hydrocarbons and pesticides (255) is already widely implemented and has proven to be successful. In some cases, there is no doubt that it is the plant itself that is responsible for the removal of the contaminants. However, in most... 

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