Mirza Babur S, Sorensen Darwin L, McGlinn Daniel J, Dupont R Ryan, McLean Joan E
Utah Water Research Laboratory, Utah State University, 8200 Old Main Hill, Logan, UT, 84322-8200, USA.
Department of Biology, College of Charleston, Charleston, SC, 29424, USA.
Appl Microbiol Biotechnol. 2017 Jun;101(11):4799-4813. doi: 10.1007/s00253-017-8180-1. Epub 2017 Feb 17.
The diversity of Dehalococcoides mccartyi (Dhc) and/or other organohalide respiring or associated microorganisms in parallel, partial, or complete trichloroethene (TCE) dehalogenating systems has not been well described. The composition of Dhc populations and the associated bacterial community that developed over 7.5 years in the top layer (0-10 cm) of eight TCE-fed columns were examined using pyrosequencing. Columns biostimulated with one of three carbon sources, along with non-stimulated controls, developed into complete (ethene production, whey amended), partial (cis-dichloroethene (DCE) and VC, an emulsified oil with nonionic surfactant), limited (<5 % cis-DCE and 95 % TCE, an emulsified oil), and non- (controls) TCE dehalogenating systems. Bioaugmentation of one column of each treatment with Bachman Road enrichment culture did not change Dhc populations nor the eventual degree of TCE dehalogenation. Pyrosequencing revealed high diversity among Dhc strains. There were 13 OTUs that were represented by more than 1000 sequences each. Cornell group-related populations dominated in complete TCE dehalogenating columns, while Pinellas group related Dhc dominated in all other treatments. General microbial communities varied with biostimulation, and three distinct microbial communities were established: one each for whey, oils, and control treatments. Bacterial genera, including Dehalobacter, Desulfitobacterium, Sulfurospirillum, Desulfuromonas, and Geobacter, all capable of partial TCE dehalogenation, were abundant in the limited and partial TCE dehalogenating systems. Dhc strain diversity was wider than previously reported and their composition within the community varied significantly depending on the nature of the carbon source applied and/or changes in the Dhc associated partners that fostered different biogeochemical conditions across the columns.
在平行、部分或完全三氯乙烯（TCE）脱卤系统中，麦氏嗜盐脱卤球菌（Dhc）和/或其他有机卤化物呼吸或相关微生物的多样性尚未得到充分描述。使用焦磷酸测序技术检测了八个TCE供料柱顶层（0-10厘米）中7.5年来形成的Dhc种群组成和相关细菌群落。用三种碳源之一进行生物刺激的柱体，以及未刺激的对照柱体，发展成为完全（产生乙烯，添加乳清）、部分（顺式二氯乙烯（DCE）和氯乙烯，含非离子表面活性剂的乳化油）、有限（<5%顺式DCE和95% TCE，乳化油）和非（对照）TCE脱卤系统。用巴赫曼路富集培养物对每种处理的一根柱体进行生物强化，既没有改变Dhc种群，也没有改变TCE脱卤的最终程度。焦磷酸测序显示Dhc菌株之间具有高度多样性。有13个操作分类单元（OTU），每个OTU都有超过1000个序列。康奈尔组相关种群在完全TCE脱卤柱中占主导地位，而皮内拉斯组相关的Dhc在所有其他处理中占主导地位。一般微生物群落随生物刺激而变化，建立了三个不同的微生物群落：乳清、油和对照处理各一个。包括脱卤杆菌属、脱硫脱硫弧菌属、硫螺旋菌属、脱硫单胞菌属和地杆菌属在内的细菌属，都能够进行部分TCE脱卤，在有限和部分TCE脱卤系统中含量丰富。Dhc菌株的多样性比以前报道的更广泛，并且它们在群落中的组成根据所应用碳源的性质和/或促进各柱不同生物地球化学条件的Dhc相关伙伴的变化而有显著差异。
