ADVANCES IN MICROBIAL BIODEGRADATION OF CHLORPYRIFOS

Abstract

Chlorpyrifos (O,O-diethyl O-3,5,6-trichloro-2-pyridyl phosphorothioate) an organophosphate pesticide is one of the most commonly used insecticide, acaricide and termiticide in agriculture, households and public health. The exposure of this moderately hazardous pesticide creates health concerns due to choline esterase inhibition, neurotoxicity, psychological and immunological effects. The microbial bioremediation of chlorpyrifos is a viable option for cleaning up the contaminated sites with its eco-friendliness, high efficiency and cost- effectiveness. Several researchers reported potential bacterial strains like Pseudomonas sp., Arthrobacter sp., Bacillus sp., Klebsiella sp., Serratia marcescens, Enterobacter sp., Stenotrophomonas sp., Sphingomonas sp., Flavobacterium sp. etc., fungal strains such as Phanerochaete chrysosporium, Aspergillus terreus, Verticillium sp., Trichoderma harzianum, etc. and cyanobacteria like Anabaena sp., Aulosira fertilissima, Phormidium valderianum for chlorpyrifos degradation. The microbes capable of producing biosurfactants increase biodegradation efficiency of chlorpyrifos by improving bioavailability of the xenobiotic compound by developing critical micellar concentration. The complete detoxification of the pesticide occurs with those microbes that also degrade its metabolites and avoid its accumulation in the environment. The cloning of mpd gene from chlorpyrifos degrading bacterial strains to Escherichia coli helps in developing its biodegradation capability. This paper focuses on the advancements in chlorpyrifos biodegradation for the efficient onsite remediation of the contaminated environment.