RESUMO
AIM: To isolate bacteria capable of degrading endosulfan (ES) and the more toxic ES sulfate and to characterize their metabolites. METHODS AND RESULTS: A Pseudomonas sp. strain IITR01 capable of degrading α-ES and toxic ES sulfate was isolated using technical-ES through enrichment culture techniques. No growth and no degradation were observed using ß-ES. Thin-layer chromatography and gas chromatography-mass spectrum analysis revealed the disappearance of both α-ES and ES sulfate and the formation of hydroxylated products ES diol, ether and lactone. We show here for the first time the formation of aforementioned metabolites in contrast to ES hemisulfate yielded by an Arthrobacter sp. Metabolism of α-ES and endosulfate was also observed using the crude cell extract of IITR01. The molecular mass of protein induced during the degradation of α-ES and sulfate as substrate was found to be approximately 150 kDa as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). CONCLUSION: We describe characterization of bacterium capable of degrading α-ES and ES sulfate but not ß-ES. Genetic investigation suggests that a gene nonhomologous to the reported esd may be present in the strain IITR01. SIGNIFICANCE AND IMPACT OF THE STUDY: This study describes toxic ES degradation by a Pseudomonas species that may be utilized for the bioremediation of the industrial soils contaminated with ES residues.
