Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
FEMS Microbiol Ecol. 2010 Apr;72(1):74-88. doi: 10.1111/j.1574-6941.2009.00825.x. Epub 2009 Dec 2.
The dynamics and composition of microbial communities in the aqueous phase of a model wetland supplied with cis- and trans-1,2-dichloroethenes (DCE)-contaminated groundwater was characterized. PCR-denaturing gradient gel electrophoresis analysis of water samples obtained from different parts of the wetland revealed that changes of the bacterial community structure coincided with a succession of the hydrochemical conditions in the wetland, from oxic towards anoxic conditions. During this transition phase, the appearance of vinyl chloride and ethene correlated with the presence of putative dechlorinating bacteria (Dehalococcoides spp., Geobacter spp. and Dehalobacter spp.). Additionally, a shift of the DCE isotopic composition indicated the progressive prevalence of reductive dechlorination in the wetland. Although the DCE degradation processes varied over time, biodegradation activity was maintained in the wetland system. 16S rRNA gene libraries revealed that Proteobacteria accounted for >50% of 16S rRNA genes clone libraries, whereas approximately 17% of the sequences from the wetland were related to sulphate reducers. Based on a multiple-method approach, this study illustrates the linkage between microbial community dynamics and composition, changes of hydrochemical conditions and processes of DCE degradation in a wetland system.
采用模型湿地，以受顺式-和反式-1,2-二氯乙烯（DCE）污染的地下水作为补充水源，研究了水相微生物群落的动态变化和组成。对取自湿地不同位置水样的 PCR-变性梯度凝胶电泳（DGGE）分析表明，细菌群落结构的变化与湿地水化学条件的变化相吻合，即从好氧条件向缺氧条件转变。在这个转变过程中，氯乙烯和乙烯的出现与推测的脱氯菌（Dehalococcoides spp.、Geobacter spp. 和 Dehalobacter spp.）的存在有关。此外，DCE 同位素组成的变化表明，在湿地中，还原脱氯作用逐渐占据主导地位。尽管 DCE 的降解过程随时间而变化，但湿地系统中的生物降解活性得以维持。16S rRNA 基因文库表明，变形菌门（Proteobacteria）占 16S rRNA 基因克隆文库的>50%，而湿地中约 17%的序列与硫酸盐还原菌有关。基于多种方法的研究表明，本研究阐明了微生物群落动态变化和组成、水化学条件变化以及湿地系统中 DCE 降解过程之间的联系。
