Reductive dechlorination of chloroethenes by Dehalococcoides-containing cultures enriched from a polychlorinated-dioxin-contaminated microcosm
Reductive dechlorination of chloroethenes by Dehalococcoides-containing cultures enriched from a polychlorinated-dioxin-contaminated microcosm
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DOI：
10.1038/ismej.2007.42
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发表时间：
2007-10-01
期刊：
影响因子：
11
通讯作者：
Hiraishi, Akira
中科院分区：
文献类型：
--
作者：
Futamata, Hiroyuki;Yoshida, Naoko;Hiraishi, Akira
采用非培养依赖和非培养依赖的方法研究了多氯二恶英脱氯微宇宙中7种富集培养物对氯乙烯的还原脱氯能力。这些培养物是用1，2，3-三氯苯（1，2，3-TCB）或苯酞作为电子受体和氢作为电子供体构建和维持的。针对16 S rRNA基因的扩增片段的变性梯度凝胶电泳（DGGE）分析显示一个或两个主要条带，然后分析其核苷酸序列，发现表明Dehalococcoides是所有富集培养物中的优势细菌之一。核苷酸序列数据显示，主带的同一性与Dehalococcoides簇的Pinellas亚组（即菌株CBDB 1和FL 2）的16 S rRNA基因序列100%相同。针对pceA，tceA，bvcA，vcrA和还原脱卤酶同源（rdh）基因进行遗传诊断，以调查培养物的还原性氯乙烯脱氯的潜力。没有观察到所需长度的PCR扩增片段，表明这些培养物不能还原性脱氯氯乙烯。然而，一项依赖于培养物的试验表明，TUT 1903和TUT 1952两种培养物可将四氯乙烯（PCE）还原为三氯乙烯（TCE），尽管不是完全脱氯。而TUT 2260和TUT 2264则将PCE完全转化为TCE和二氯乙烯，但不会进一步转化。这些结果表明，这些TUT文化可能包括一种新的类型的细菌属于Dehalococcoides组和目前可用的信息都16 S rRNA基因和rdh基因序列是不够的，以明确评估还原脱氯的潜在能力。
The reductive dechlorinating abilities for chloroethenes of seven enrichment cultures from polychlorinated-dioxin-dechlorinating microcosm were investigated using culture-independent and -dependent methods. These cultures were constructed and maintained with 1,2,3-trichlorobenzene (1,2,3-TCB) or fthalide as an electron acceptor and hydrogen as an electron donor. Denaturing gradient gel electrophoresis (DGGE) analysis of the amplified fragments targeting the 16S rRNA gene showed one or two major bands, whose nucleotide sequences were then analyzed and were found to suggest that Dehalococcoides was one of the dominant bacteria in all enrichment cultures. The nucleotide sequence data revealed that the identity of the major band was 100% identical to the 16S rRNA gene sequence of the Pinellas subgroup of the Dehalococcoides clusters, that is, strains CBDB1 and FL2. Genetic diagnosis targeting the pceA, tceA, bvcA, vcrA and reductive dehalogenase homologous (rdh) gene was performed to investigate the potential for reductive chloroethene dechlorination of cultures. The required length of PCR-amplified fragments was not observed, suggesting that these cultures are not capable of reductively dechlorinating chloroethenes. However, a culture-dependent test indicated that two cultures, TUT1903 and TUT1952, reductively dechlorinated tetrachloroethene (PCE) to trichloroethene (TCE), although not completely. While, TUT2260 and TUT2264 completely converted PCE to TCE and dichloroethenes, but not further. These results suggest that these TUT cultures might include a novel type of bacteria belonging to the Dehalococcoides group and that currently available information on both the 16S rRNA gene and rdh gene sequences is insufficient to definitively evaluate the potential abilities for reductive dechlorination.