Endosulfan is one among the Stockholm listed persistent organochlorine pesticide which was widely used in India against various pests of agriculture and plantation crops. Its low solubility limits its biodegradation in the water and soil. The present study aims to formulate a bacterial consortium comprising of biosurfactant producing bacteria capable to mineralize endosulfan isomers and its metabolite endosulfate. Screened bacterial isolates capable of producing biosurfactant and degrade endosulfan was grouped to produce nine bacterial consortium comprising of three bacterial strains each. These nine consortia were tested for endosulfan degradation. All the bacterial consortia (A, B, C, D, E, F, G, H and I) were able to degrade between 65% and 80% of endosulfan in twelve days. Degradation was faster in case of consortium F with a degradation of 81% of α endosulfan and β endosulfan in eight days. Further the consortium F was checked for complete mineralization of endosulfan. Analysis of intermediates revealed the presence of metabolites of endosulfan mainly endosulfate, endosulfan diol, endosulfan ether and phthalic acid. In the present study, complete mineralization of endosulfan by consortium F was confirmed based on the carbon dioxide and chloride ion released during the biodegradation of endosulfan. The study revealed that the consortium comprising of biosurfactant producing bacteria was able to enhance the degradation of endosulfan and mineralize endosulfan.
Keywords : Bioavailability, endosulfan, biodegradation, biosurfactants, Bordetella petrii, endosulfate.