Biodegradation of Endosulfan in Broth Medium and in Soil Microcosm by Klebsiella sp M3

Nine endosulfan degrading bacterial strains were isolated by soil enrichment with endosulfan. Bacterial strain M3 was the most efficient degrader. Endosulfan degradation was accompanied by a decrease in pH of the medium and an increase in chloride ion concentration. The bacterium was tested for its ability to degrade endosulfan at different concentrations in broth and soil. Maximum degradation occurred at concentrations of 50 mu g/ml of broth and 100 mu g/g of soil. Values of K-s and V-max were different for (alpha)- and (beta)-endosulfan in broth. The kinetic indices (V-max/K-s) for alpha-endosulfan and beta-endosulfan were 0.051 and 0.048 day(-1) respectively, indicating that (alpha)-endosulfan was more rapidly degraded. Bacterial strain M3 was identified as Klebsiella sp. M3 on the basis of 16S rDNA sequence similarity (GenBank accession number JX273762).