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 μg/ml of broth and 100 μg/g of soil. Values of Ks and Vmax were different for (α)- and (β)-endosulfan in broth. The kinetic indices (Vmax/Ks) for α-endosulfan and β-endosulfan were 0.051 and 0.048 day−1 respectively, indicating that (α)-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).