Degradation of Chlorpyrifos by Indigenous Soil Bacteria

Four chlorpyrifos degrading bacterial isolates were recovered from pesticide contaminated soil of the University campus. All the isolates were fast grower and showed enhanced growth and pesticide degradation in the presence of sodium glutamate at neutral pH in minimal medium. Fifty percent degradation of chlorpyrifos was observed in minimal medium after 9, 11, 8, and 7 d by S1, S8, S9 and S12 isolate respectively. Two isolates (S9 and S12) tolerated up to 90 μg ml−1 chlorpyrifos and degraded the compound > 90% in 30 d in minimal medium. Bacterial consortium consisting of S9 and S12 degraded chlorpyrifos in the range of 99.13% and 98.5% under unsterilized and sterilized soil columns respectively in 30 d. Phenotypic and molecular characterization of S9 and S12 revealed their similarity with Bacillus and Pseudomonas sps. respectively.