Zhou Xue, Zhang Chunfang, Zhang Dongdong, Awata Takanori, Xiao Zhixing, Yang Qi, Katayama Arata
School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China; Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8603, Japan.
Institute of Marine Biology, Ocean College, Zhejiang University, Hangzhou 310058, China; EcoTopia Science Institute, Nagoya University, Nagoya 464-8603, Japan.
J Biosci Bioeng. 2015 Jul;120(1):62-8. doi: 10.1016/j.jbiosc.2014.11.023. Epub 2015 Mar 17.
An anaerobic consortium that was capable of reductively dechlorinating hexachlorobenzene (HCB) to benzene was enriched from contaminated sediment. The consortium was capable of dechlorinating all chlorobenzene isomers except 1,4-dichlorobenzene. Singly and doubly flanked chlorines, as well as unflanked meta-substituted chlorines, were dechlorinated, although doubly flanked chlorines were preferred. Formate, acetate and lactate (but not ethanol) could be utilized as optimum electron donors for reductive dechlorination. Alternative electron acceptors, including nitrate and sulfate, completely inhibited HCB degradation, whereas amorphous iron oxide (FeOOH) did not suppress dechlorination activity. No degradation was found in chloramphenicol-treated consortium; however, vancomycin, molybdate, and 2-bromoethanesulfonate did not inhibit HCB dechlorination. The results of inhibitory treatments suggested that the dechlorinators were non-sulfate-reducing gram-negative or vancomycin resistant gram-positive bacteria. In addition to physiological characterization, analyses of 16S rRNA gene library of the consortium and quantitative PCR of 16S rRNA genes suggested that Dehalococcoides sp. was involved in the reductive dechlorination of HCB, and Geobacter sp. may serve as a dechlorinating candidate.
从受污染的沉积物中富集得到了一个厌氧菌群，该菌群能够将六氯苯（HCB）还原脱氯为苯。该菌群能够对除1,4 - 二氯苯之外的所有氯苯异构体进行脱氯。单侧翼和双侧翼的氯，以及无侧翼的间位取代氯均能被脱氯，不过双侧翼氯更易被脱氯。甲酸盐、乙酸盐和乳酸盐（而非乙醇）可用作还原脱氯的最佳电子供体。包括硝酸盐和硫酸盐在内的替代电子受体完全抑制了六氯苯的降解，而无定形氧化铁（FeOOH）并未抑制脱氯活性。氯霉素处理过的菌群未发现降解现象；然而，万古霉素、钼酸盐和2 - 溴乙烷磺酸盐并未抑制六氯苯的脱氯。抑制处理结果表明，脱氯菌为非硫酸盐还原革兰氏阴性菌或万古霉素抗性革兰氏阳性菌。除了生理特性表征外，对该菌群16S rRNA基因文库的分析以及16S rRNA基因的定量PCR表明，脱卤球菌属（Dehalococcoides sp.）参与了六氯苯的还原脱氯，而地杆菌属（Geobacter sp.）可能是一种脱氯候选菌。
