Toxicity and Genetic Basis of Microbial Degradation of Organophosphorus Pesticides

The industrialization of the agricultural sector has made pesticides an inevitable part of the modern environment. The term pesticide covers a wide range of compounds including herbicides, insecticides, nematicides, fungicides, and others which eradicate the pests that cause economic damage to crops besides soil pollution. Protecting crops from pest attacks is therefore very critical and thus with urbanization and the growing world population, pesticide production and use have become unavoidable. Organophosphate (OP) pesticides are probably the most commercially preferred category of pesticides, with broad areas of application in horticulture, agriculture, pest control, etc. Although OPs have biodegradability potential, the exposure to OPs leads to varying levels of toxicity in plants, animals, and humans. Different methods are being employed in the process of detoxification of these compounds. In the pro tern, bioremediation is preferred as a compatible way in the present era because it involves the use of biological systems to clean up contaminated sites with no toxic effects. Various microorganisms (i.e., bacteria, fungi) have been reported with the ability to degrade different organophosphate pesticides via enzymes for their growth. The mechanism of degradation of organophosphate pesticides remains same in most bacterial species. Manipulating this mechanism for the production of these enzymes by means of genetic engineering (GE) tools will result in mass production of recombinant organisms possessing the genes coding for those enzymes. Recently, engineered microorganisms are employed to degrade 380different organophosphorus pollutants, including nerve agents due to its high efficiency. This chapter emphasizes on the toxicity of organophosphate pesticides, various microbial degradation strategies and the mechanism of degradation of widely used organophosphate pesticides at global level.