The biotransformation of hexachlorocyclohexane isomers (HCH) by two Dehalococcoides mccartyi strains (195 and BTF08) and an enrichment culture was investigated and compared to conversion by the obligate anaerobic strain Clostridium pasteurianum strain DSMZ 525. The D. mccartyi strains preferentially transformed γ-HCH over α-HCH and δ-HCH isomers while β-HCH biotransformation was not significant. In case of the enrichment culture, γ-HCH was preferentially transformed over the δ-HCH, β-HCH and α-HCH isomers. Major observed metabolites in both cases were tetrachlorocyclohexene and as end products monochlorobenzene (MCB) and benzene. Dechlorination of the γ-HCH isomer was linked to an increase in cell numbers for strain 195. γ-HCH transformation was linked to considerable carbon stable isotope fractionation with the enrichment factor ε_c = − 5.5 ± 0.8‰ for D. mccartyi strain 195, ε_c = − 3.1 ± 0.4‰ for the enrichment culture and ε_c = − 4.1 ± 0.6‰ for co-metabolic transformation by C. pasteurianum.

中文翻译：

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Dehaloccocoides物种和富集培养对六氯环己烷异构体进行厌氧生物转化。

研究了两个Dehalococcoides mccartyi菌株（195和BTF08）对六氯环己烷异构体（HCH）的生物转化以及富集培养，并将其与专性厌氧巴氏梭菌DSMZ 525的转化进行了比较。菌株比α-HCH和δ-HCH异构体优先转化γ-HCH，而β-HCH的生物转化并不显着。在富集培养的情况下，相对于δ-HCH，β-HCH和α-HCH异构体，γ-HCH优先转化。在这两种情况下，观察到的主要代谢物均为四氯环己烯，其终产物为一氯苯（MCB）和苯。异构体是有联系的增加应变195.γ-HCH转化细胞数的γ-HCH的脱氯链接到与富集因子相当大的碳的稳定同位素分馏ε _Ç  = - 5.5±0.8‰为D. mccartyi菌株195， ε _ç  = - 3.1±0.4‰的富集培养物和ε _ç  = - 4.1±0.6‰，通过共代谢转化C.巴氏。