AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria.
AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria.
Environ Sci Pollut Res Int. 2017 Nov;24(32):24803-24815. doi: 10.1007/s11356-017-0075-2. Epub 2017 Sep 15.
Reductive dechlorination performed by organohalide-respiring bacteria (OHRB) enables the complete detoxification of certain emerging groundwater pollutants such as perchloroethene (PCE). Environmental samples from a contaminated site incubated in a lab-scale microcosm (MC) study enable documentation of such reductive dechlorination processes. As compound-specific isotope analysis is used to monitor PCE degradation processes, nucleic acid analysis-like 16S-rDNA analysis-can be used to determine the key OHRB that are present. This study applied both methods to laboratory MCs prepared from environmental samples to investigate OHRB-specific isotope enrichment at PCE dechlorination. This method linkage can enhance the understanding of isotope enrichment patterns of distinct OHRB, which further contribute to more accurate evaluation, characterisation and prospection of natural attenuation processes. Results identified three known OHRB genera (Dehalogenimonas, Desulfuromonas, Geobacter) in diverse abundance within MCs. One species of Dehalogenimonas was potentially involved in complete reductive dechlorination of PCE to ethene. Furthermore, the isotopic effects of PCE degradation were clustered and two isotope enrichment factors (ε) (- 11.6‰, - 1.7‰) were obtained. Notably, ε values were independent of degradation rates and kinetics, but did reflect the genera of the dechlorinating OHRB.
有机卤化物呼吸细菌（OHRB）的还原脱氯作用使某些新兴地下水污染物如全氯乙烯（PCE）得以完全解毒。在实验室规模的微宇宙（MC）研究中对污染场地的环境样本进行培养，使还原脱氯过程得以记录。由于化合物特异性同位素分析用于监测 PCE 降解过程，因此可以像 16S-rDNA 分析一样进行核酸分析，以确定存在的关键 OHRB。本研究应用这两种方法对来自环境样本的实验室 MC 进行了研究，以调查 PCE 脱氯过程中 OHRB 特异性同位素富集。这种方法的结合可以增强对不同 OHRB 同位素富集模式的理解，从而有助于更准确地评估、描述和预测自然衰减过程。结果在 MC 中以不同丰度确定了三种已知的 OHRB 属（Dehalogenimonas、Desulfuromonas、Geobacter）。一种 Dehalogenimonas 物种可能参与了 PCE 向乙烯的完全还原脱氯。此外，PCE 降解的同位素效应被聚类，获得了两个同位素富集因子（ε）（-11.6‰，-1.7‰）。值得注意的是，ε 值独立于降解速率和动力学，但确实反映了脱卤 OHRB 的属。
