Enhanced Degradation And Detoxification Of Endosulfan In Two Kinds Of Soil By Degrading Bacteria JBW4

The research object of this paper is endosulfan.This paper also determined the detoxification of endosulfan by degrading-bacteria JBW4in red soil and black soil.The degradation of JBW4, the colonization of JBW4in the two kinds of endosulfan contaminated soil, genotoxicity changes of endosulfan before and after degradation, the degradation product were studied. The results have been obtained as follows:l.The degradation of JBW4which was isolated by our laboratory,in red soil and black soil,was studied.This study had four treatmens of sterilized soil with endosulfan(SE), natural soil with endosulfan(NE),sterilized soil with endosulfan and degradation-strain(SEJ),natural soil with endosulfan and degradation-strain(SEJ),and samples were collected at0,3,7,14,21,28,35,49,63,77d to extract the residual endosulfan in soil.The results showed the half-life of a-endosulfan in SE, NE, SEJ, NEJ in red soil were129.3,111.9,42.1,32.4d;β-endosulfan were175,162.6,65.7,50.4d.In black soil, the half-life of a-endosulfan in SE, NE, SEJ, NEJ were63.9,31.8,20.9,16.3d; β-endosulfan were105.8,82.32,50.46,39.0d.It appears that JBW4was able to degrade α-and β-endosulfan and promoted this degradation.However,the degradation of endosulfan in red soil was faster than that in black soil.2. The method of PCR-DGGE has been applied to investigate the establishment of JBW4strain in the soil. This study investigated the colonization of JBW4strains in3,5,7d in red soil and black soil.Through the control bar with DNA electrophoresis,the target bands of JBW4are clear and bright,indicating that JBW4could successfully colonize in the red soil and black soil.3.In this study, we choose Eisenia foetida as experimental material and the method of extraction by water was used. Through exposure of the filter paper method, earthworms degree of DNA damage were detected by comet assay. The evaluation index was used to determine the degradation changes before and after the soil genotoxicity. The effect of endosulfan on earthworm was tested on the3rd,21st,49th,and77th day afer the different treatments. The results show that the olive tail moment(OTM) of the treatment with strain was shorter than that of the treatment without strain.The genetic toxicity of the soil significantly reduced after inoculation JBW4strain. 4. In our research, endosulfan metabolites were identified by GC-MS. The results show that endosulfan lactone and endosulfan ether was detected as the major intermediate metabolites.The results suggest that strain JBW4might degrade endosulfan by a hydrolysis pathway.The pathway of endosulfan degradation:endosulfanâ†'Endosulfan diolâ†'Endosulfan lactone.