Although the anaerobic biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) has been documented in the laboratory and the field, knowledge of the microorganisms and mechanisms involved is still lacking. In this study, DNA-stable isotope probing (SIP) was used to identify microorganisms involved in anaerobic fuel oxygenate biodegradation in a sulfate-reducing MTBE and TBA plume. Microorganisms were collected in the field using Bio-Sep® beads amended with 13C5-MTBE, 13C1-MTBE (only methoxy carbon labeled), or13C4-TBA. 13C-DNA and 12C-DNA extracted from the Bio-Sep beads were cloned and 16S rRNA gene sequences were used to identify the indigenous microorganisms involved in degrading the methoxy group of MTBE and the tert-butyl group of MTBE and TBA. Results indicated that microorganisms were actively degrading 13C-labeled MTBE and TBA in situ and the 13C was incorporated into their DNA. Several sequences related to known MTBE- and TBA-degraders in the Burkholderiales and the Sphingomonadales orders were detected in all three13C clone libraries and were likely to be primary degraders at the site. Sequences related to sulfate-reducing bacteria and iron-reducers, such as Geobacter and Geothrix, were only detected in the clone libraries where MTBE and TBA were fully labeled with 13C, suggesting that they were involved in processing carbon from the tert-butyl group. Sequences similar to the Pseudomonas genus predominated in the clone library where only the methoxy carbon of MTBE was labeled with 13C. It is likely that members of this genus were secondary degraders cross-feeding on 13C-labeled metabolites such as acetate.

中文翻译：

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使用DNA稳定同位素探测来识别受污染的地下水中的MTBE和TBA降解微生物。

尽管实验室和该领域已对甲基叔丁基醚（MTBE）和叔丁醇（TBA）进行厌氧生物降解，但仍缺乏有关微生物和机制的知识。在这项研究中，DNA稳定同位素探测（SIP）用于鉴定减少硫酸盐的MTBE和TBA羽流中厌氧燃料含氧物生物降解的微生物。使用经13C5-MTBE，13C1-MTBE（仅被甲氧基碳标记）或13C4-TBA修饰的珠子，在野外收集微生物。克隆了从Bio-Sep珠中提取的13C-DNA和12C-DNA，并使用16S rRNA基因序列鉴定了涉及降解MTBE的甲氧基和MTBE和TBA的叔丁基的本地微生物。结果表明，微生物正在原位主动降解13C标记的MTBE和TBA，并将13C掺入其DNA中。在所有三个13C克隆文库中都检测到了与Burkholderiales和Sphingomonadales订单中已知的MTBE和TBA降解子有关的几个序列，它们很可能是该位点的主要降解子。仅在克隆文库中检测到了与硫酸盐还原细菌和铁还原剂相关的序列，例如Geobacter和Geothrix，该克隆库中MTBE和TBA被13C完全标记，表明它们参与了叔丁基碳的加工。克隆库中与假单胞菌属相似的序列占优势，其中仅MTBE的甲氧基碳被13C标记。