Endosulfan mineralization by bacterial isolates and possible degradation pathway identification

A bacterial consortium consists of three bacterial isolates, which rapidly mineralizes endosulfan, was enriched from an endosulfan-processing industrial surface soil. Batch experiments were conducted using bacterial consortium and its pure isolates for their potential degradation of endosulfan and its metabolites, i.e., endosulfan sulfate, endosulfan ether, and endosulfan lactone, in anaerobic condition. Endosulfan degradation was promising with bacterial consortium and pure isolates. Staphylococcus sp. preferably utilized beta endosulfan whereas other two Bacillus strains utilized more alpha endosulfan. The addition of supplementary carbon, i.e., dextrose, stimulated the endosulfan degradation efficiency in both the cases. Degradation of endosulfan ether and endosulfan lactone was promising with Bacillus circulans I and II whereas no endosulfan sulfate was degraded by any of these strains. From the present investigation, it was postulated that endosulfan was mineralized via hydrolysis pathway with the formation of carbenium ions and/or ethylcarboxylates, which later converted into simple hydrocarbons. © 2006 Taylor and Francis Group, LLC.