Biodegradation of Endosulfan by Bacterial Strain Alcaligenes faecalis JBW4 in Argi-Udic Ferrosols and Hapli-Udic Isohumosols

摘要

The overapplication of endosulfan on crops has resulted in the widespread contamination of soil. In this study, we examine the potential for bioremediation of the bacteria strain Alcaligenes faecalis JBW4 in degrading endsosulfan in soils. Bacteria were inoculated into sterilized and non-sterilized soils (Argi-Udic Ferrosols and Hapli-Udic Isohumosols) spiked with endosulfan. The results obtained from polymerase chain reaction-denaturing gradient gel electrophoresis indicate that JBW4 colonized Argi-Udic Ferrosols and Hapli-Udic Isohumosols successfully. The degradation efficiencies of alpha and beta isomers of endosulfan by JBW4 were higher in Hapli-Udic Isohumosols than in Argi-Udic Ferrosols, and alpha and beta isomers were degraded by 100.0 and 69.8%, respectively. In addition, detected endosulfan metabolites were either endosulfan ether and endosulfan lactone. Results of the single-cell gel electrophoresis assay showed that the toxicity of endosulfan and its metabolites in Hapli-Udic Isohumosols decreased after 77 days when compared to those in Argi-Udic Ferrosols after degradation by JBW4. Strain JBW4 is an excellent bioremediator through its ability to degrade endosulfan in contaminated Argi-Udic Ferrosols and Hapli-Udic Isohumosols.