Microbial Degradation of Organophosphate Pesticides: A Review

Pesticides have become an inevitable part of the modern environment as they are widely used in agriculture, household, and public health sectors and, hence, are extensively distributed throughout most ecosystems. Currently, organophosphate pesticides are the most commercially favored group of pesticides, with large application areas all over the world. Depending on their fate, these organophosphorus compounds may become bioavailable for microbial degradation. Environmental microbes, such as Aspergillus, Pseudomonas, Chlorella, and Arthrobacter, are capable of coupling a variety of physical and biochemical mechanisms for the degradation of organophosphate pesticides, including adsorption, hydrolysis of P-O alkyl and aryl bonds, photodegradation, and enzymatic mineralization. Enzymes, such as esterase, diisopropyl fluorophosphatase, phosphotriesterase, somanase, parathion hydrolase, and paraoxonase, have been isolated from microbes to study and understand the catabolic pathways involved in the biotransformation of these xenobiotic compounds. This review highlights various aspects of biodegradation of organophosphate pesticides along with biological and molecular characterization of some organophosphate pesticide-degrading bacteria.