Yang Yanru, Pesaro Manuel, Sigler William, Zeyer Josef
ETH Zurich, Institute of Terrestrial Ecology, Soil Biology, Grabenstrasse 3, CH-8952 Schlieren, Switzerland.
Water Res. 2005 Oct;39(16):3954-66. doi: 10.1016/j.watres.2005.07.010.
In this study, we report on phylogenetic and physiological characterization of an anaerobic culture capable of reductive dehalogenation of tetrachloroethene (PCE) obtained from a PCE-contaminated site. The culture was enriched using different combinations of electron donors (hydrogen and acetate) and electron acceptors (PCE, cis-1,2-dichloroethene (cDCE) and controls without chlorinated ethenes). The resulting subcultures were analyzed using three different approaches: chemical analysis to document conversion of chlorinated ethenes; polymerase chain reaction (PCR) of 16S rRNA gene fragments and denaturing gradient gel electrophoresis (DGGE) to compare community compositions; fluorescence in situ hybridization (FISH) to quantify specific groups of microorganisms using oligonucleotide probes previously designed or newly designed based on the sequences retrieved from sequence analysis of specific DGGE bands. Members of two genera which contain bacteria capable of reductive dehalogenation were detected in the culture: Dehalococcoides and Desulfitobacterium. The combined analyses suggested that Dehalococcoides-like bacteria are associated with complete dehalogenation of chlorinated ethenes to ethene with hydrogen as electron donor; and Desulfitobacterium-like bacteria, in contrast, are associated with incomplete PCE dehalogenation to cDCE and appear to be able to use acetate as electron donor. In addition, Sporomusa-like bacteria were identified, which most likely act as homoacetogens. The results demonstrated that combination of culture enrichment with different substrates, DGGE, and FISH allowed a detailed qualitative and quantitative characterization of the dominant microorganisms associated with reductive dehalogenation.
在本研究中，我们报告了从一个受四氯乙烯（PCE）污染的场地获得的、能够对四氯乙烯进行还原脱卤的厌氧培养物的系统发育和生理特征。使用电子供体（氢气和乙酸盐）和电子受体（PCE、顺式-1,2-二氯乙烯（cDCE）以及不含氯乙烯的对照物）的不同组合对该培养物进行富集。使用三种不同方法对所得的传代培养物进行分析：化学分析以记录氯乙烯的转化情况；16S rRNA基因片段的聚合酶链反应（PCR）和变性梯度凝胶电泳（DGGE）以比较群落组成；荧光原位杂交（FISH），使用基于从特定DGGE条带的序列分析中检索到的序列预先设计或新设计的寡核苷酸探针来定量特定微生物群体。在该培养物中检测到了两个含有能够进行还原脱卤的细菌的属的成员：脱卤球菌属和脱硫脱硫弧菌属。综合分析表明，类似脱卤球菌的细菌与以氢气作为电子供体将氯乙烯完全脱卤为乙烯有关；相反，类似脱硫脱硫弧菌的细菌与PCE不完全脱卤为cDCE有关，并且似乎能够使用乙酸盐作为电子供体。此外，还鉴定出了类似芽孢杆菌属的细菌，它们很可能作为同型产乙酸菌起作用。结果表明，将不同底物的培养物富集与DGGE和FISH相结合，能够对与还原脱卤相关的优势微生物进行详细的定性和定量表征。
