Microbial degradation of pesticide: A review

Excessive use of pesticides has been known to be hazardous to the environment, affect soil fertility as well may impart toxicity in living beings. Presently there have been physical, chemical, biological and enzymatic approaches implicated to reduce pesticides. Although aimed to eradicate, physical and chemical methods are inefficient. Curiously, microbial pesticide remediation has been cost effective and thermodynamically more affordable, which may use any physical mater soiled with pesticide. Under favourable conditions microbes have been reported to use pesticides as source of carbon, sulphur and electron donor. Microbes; bacteria, actinomycetes and fungi have been found to help remove or detoxify chlorinated pesticides; polychlorinated diphenyl, polycyclic aromatic hydrocarbons, organophosphorus. Major bacterial genera includes; Bacillus, Pseudomonas, Flavobacterium, Moraxalla, Acinetobacter, Arthrobacter, Paracoccus, Aerobacter, Alkaligens, Burkholderia and Sphingomonas. Fungi with pesticide degradation potential includes;Fusarium, Aspergilus niger, Penicillium, Lentinulaedodes, Lecanicillium, Oxysporum. Among the Actinomycetes theStreptomycetes have been found to successfully detoxify pesticides. Persistent organic pollutants in the form of pesticides have also been reported to be taken care by the microbial enzymes viz-a-viz; dehydrogenase, ligninase, oxygenase, peroxidises, phosphotriesterase, hydrolases, dehalogenase, laccase and organophosphorus acid anhydrolase. Microbial strategies and tools; enzymes and genes involved in pesticide catabolism are reviewed. Key words: Chlorinated pesticides, organophosphors pesticides, bacteria, fungi, enzyme.