Polybrominated diphenyl ethers (PBDEs) are persistent pollutants that may undergo microbial-mediated debromination in anoxic environments, where diverse anaerobic microbes such as methanogenic archaea co-exist. However, current understanding of the relations between PBDE pollution and methanogenic process is far from complete. To address this knowledge gap, a series of anaerobic soil microcosms were established. BDE-47 (2, 2′, 4, 4′-tetrabromodiphenyl ether) was selected as a model pollutant, and electron donors were supplied to stimulate the activity of anaerobes. Debromination and methane production were monitored during the 12 weeks incubation, while obligate organohalide-respiring bacteria (OHRBs), methanogenic, and the total bacterial communities were examined at week 7 and 12. The results demonstrated slow debromination of BDE-47 in all microcosms, with considerable growth of and over the incubation observed in most BDE-47 spiked treatments. In addition, the accumulation of intermediate metabolites positively correlated with the abundance of at week 7, suggesting potential role of these OHRBs in debromination. were identified as the primary methanogenic archaea, and their abundance were correlated with the production of debrominated metabolites at week 7. Furthermore, it was observed for the first time that BDE-47 considerably enhanced methane production and increased the abundance of genes, highlighting the potential effects of PBDE pollution on climate change. This might be related to the inhibition of reductive N- and S-transforming microbes, as revealed by the quantitative microbial element cycling (QMEC) analysis. Overall, our findings shed light on the intricate interactions between PBDE and methanogenic processes, and contribute to a better understanding of the environmental fate and ecological implication of PBDE under anaerobic settings.

中文翻译：

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厌氧土壤微观世界中 2, 2′, 4, 4′-四溴二苯醚 (BDE-47) 脱溴与产甲烷作用的耦合

多溴二苯醚 (PBDE) 是一种持久性污染物，在缺氧环境中可能会发生微生物介导的脱溴作用，在缺氧环境中，产甲烷古菌等多种厌氧微生物共存。然而，目前对PBDE污染与产甲烷过程之间关系的认识还很不完整。为了弥补这一知识差距，建立了一系列厌氧土壤微观世界。选择BDE-47（2,2',4,4'-四溴二苯醚）作为模型污染物，并提供电子供体来刺激厌氧菌的活性。在 12 周的孵化期间监测脱溴和甲烷产生，同时在第 7 周和第 12 周检查专性有机卤化物呼吸细菌 (OHRB)、产甲烷菌和总细菌群落。结果表明 BDE-47 在所有微观世界中缓慢脱溴，在大多数加标 BDE-47 的处理中观察到在孵化期间和孵化期间都有相当大的生长。此外，中间代谢物的积累与第 7 周时的丰度呈正相关，表明这些 OHRB 在脱溴中的潜在作用。被鉴定为主要产甲烷古菌，其丰度与第 7 周时脱溴代谢物的产生相关。此外，首次观察到 BDE-47 显着增强了甲烷产生并增加了基因丰度，凸显了潜在的潜力。 PBDE 污染对气候变化的影响。定量微生物元素循环 (QMEC) 分析表明，这可能与还原性 N 和 S 转化微生物的抑制有关。总体而言，我们的研究结果揭示了 PBDE 与产甲烷过程之间复杂的相互作用，并有助于更好地了解厌氧环境下 PBDE 的环境命运和生态影响。