Hermon Louis, Hellal Jennifer, Denonfoux Jérémie, Vuilleumier Stéphane, Imfeld Gwenaël, Urien Charlotte, Ferreira Stéphanie, Joulian Catherine
Geomicrobiology and Environmental Monitoring Unit, Bureau de Recherches Géologiques et Minières (BRGM), Orléans, France.
CNRS, GMGM UMR 7156, Genomics and Microbiology, Université de Strasbourg, Strasbourg, France.
Front Microbiol. 2019 Feb 12;10:89. doi: 10.3389/fmicb.2019.00089. eCollection 2019.
Microcosm experiments with CE-contaminated groundwater from a former industrial site were set-up to evaluate the relationships between biological CE dissipation, dehalogenase genes abundance and bacterial genera diversity. Impact of high concentrations of PCE on organohalide respiration was also evaluated. Complete or partial dechlorination of PCE, TCE, -DCE and VC was observed independently of the addition of a reducing agent (NaS) or an electron donor (acetate). The addition of either 10 or 100 μM PCE had no effect on organohalide respiration. qPCR analysis of reductive dehalogenases genes (, and ) indicated that the version of gene found in the genus [hereafter named (Dhc)] and gene increased in abundance by one order of magnitude during the first 10 days of incubation. The version of the gene found, among others, in the genus , and [hereafter named (Dhb)] and gene showed very low abundance. The gene was not detected throughout the experiment. The proportion of (Dhc) or genes relative to the universal 16S ribosomal RNA (16S rRNA) gene increased by up to 6-fold upon completion of DCE dissipation. Sequencing of 16S rRNA amplicons indicated that the abundance of Operational Taxonomic Units (OTUs) affiliated to dehalogenating genera , and represented more than 20% sequence abundance in the microcosms. Among organohalide respiration associated genera, only abundance of spp. increased up to fourfold upon complete dissipation of PCE and -DCE, suggesting a major implication of in CEs organohalide respiration. The relative abundance of and genes correlated with the occurrence of and with dissipation extent of PCE, -DCE and CV. A new type of dehalogenating sp. phylotype affiliated to the Pinellas group, and suggested to contain both (Dhc) and genes, may be involved in organohalide respiration of CEs in groundwater of the study site. Overall, the results demonstrate dechlorination potential of CE in the plume, and suggest that taxonomic and functional biomarkers in laboratory microcosms of contaminated groundwater following pollutant exposure can help predict bioremediation potential at contaminated industrial sites.
开展了微宇宙实验，使用来自某 former 工业场地的受 CE 污染的地下水，以评估生物 CE 降解、脱卤酶基因丰度和细菌属多样性之间的关系。还评估了高浓度 PCE 对有机卤呼吸的影响。观察到 PCE、TCE、-DCE 和 VC 的完全或部分脱氯，这与是否添加还原剂（NaS）或电子供体（乙酸盐）无关。添加 10 或 100 μM 的 PCE 对有机卤呼吸没有影响。对还原性脱卤酶基因（、和）的 qPCR 分析表明，在属中发现的基因版本[以下称为（Dhc）]和基因在培养的前 10 天内丰度增加了一个数量级。在属、和等中发现的基因版本[以下称为（Dhb）]和基因丰度非常低。在整个实验过程中未检测到基因。DCE 降解完成后，（Dhc）或基因相对于通用的 16S 核糖体 RNA（16S rRNA）基因的比例增加了高达 6 倍。16S rRNA 扩增子测序表明，与脱卤属、和相关的操作分类单元（OTU）的丰度在微宇宙中占序列丰度的 20%以上。在与有机卤呼吸相关的属中，只有 spp.的丰度在 PCE 和 -DCE 完全降解后增加了四倍，这表明在 CE 的有机卤呼吸中起主要作用。和基因的相对丰度与的出现以及 PCE、-DCE 和 CV 的降解程度相关。一种与 Pinellas 组相关的新型脱卤菌属系统发育型，被认为同时含有（Dhc）和基因，可能参与了研究场地地下水中 CE 的有机卤呼吸。总体而言，结果证明了羽流中 CE 的脱氯潜力，并表明在受污染地下水的实验室微宇宙中，污染物暴露后的分类和功能生物标志物有助于预测受污染工业场地的生物修复潜力。
