title: Polyphasic characterization of an anaerobic hexachlorobenzene-dechlorinating microbial consortium with a wide dechlorination spectrum for chlorobenzenes.
abstract: 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.
authors: 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.
authors: Xue
authors: X
authors: Zhou
authors: Institute of Marine Biology, Ocean College, Zhejiang University, Hangzhou 310058, China; EcoTopia Science Institute, Nagoya University, Nagoya 464-8603, Japan.
authors: Chunfang
authors: C
authors: Zhang
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Dongdong
authors: D
authors: Zhang
authors: EcoTopia Science Institute, Nagoya University, Nagoya 464-8603, Japan; Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Takanori
authors: T
authors: Awata
authors: Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors: Zhixing
authors: Z
authors: Xiao
authors: School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China.
authors: Qi
authors: Q
authors: Yang
authors: Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8603, Japan; EcoTopia Science Institute, Nagoya University, Nagoya 464-8603, Japan; Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan. Electronic address: a-katayama@esi.nagoya-u.ac.jp.
authors: Arata
authors: A
authors: Katayama
mesh_terms: D000693:Anaerobiosis; D002713:Chlorine / Q000378:metabolism*; D002722:Chlorobenzenes / Q000378:metabolism; D041862:Chloroflexi / Q000235:genetics / Q000378:metabolism; D020459:Genes, rRNA / Q000235:genetics; D045302:Geobacter / Q000235:genetics / Q000378:metabolism; D054879:Halogenation; D006581:Hexachlorobenzene / Q000737:chemistry* / Q000378:metabolism*; D059013:Microbial Consortia / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D010084:Oxidation-Reduction / Q000187:drug effects; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D002722:Chlorobenzenes; D012336:RNA, Ribosomal, 16S; D002713:Chlorine; D006581:Hexachlorobenzene; C018511:4-dichlorobenzene
keywords: Chlorobenzenes; Dehalococcoides sp.; Full reductive dechlorination; Geobacter sp.; Hexachlorobenzene