POTENTIAL CHLORPYRIFOS AND MALATHION DEGRADING BACTERIAL ISOLATION, BIOCHEMICAL CHARACTERIZATION AND GROWTH KINETICS STUDIES

Soil bacterium capable of utilizing organophosphate based pesticides as sole carbon source was isolated by selective enrichment on mineral medium containing chlorpyrifos and malathion individually. A total eleven bacterial isolates were isolated from five different agriculture soils. The pesticide tolerance test revealed that MGPD-02 was high potential isolate against chlorpyrifos and malation, biochemical characteristics revealed that MGPD-02 was gram negative bacilli citrate, nitrate reductase, MR and VP positive bacteria. Growth studies showed that MGPD-02 utilized chlorpyrifos to grow in Luria-Bertani broth containing different concentrations of chlorpyrifos at 50 -500 ppm. However, the optimum concentration that supported bacterial growth over 24 h was found to be 50 -200 ppm. Further concentrations were proved to be decreasing their bacterial growth and become completely lethal at 500 ppm for both chlorpyrifos and malathion.