Department of Biology, Georgia State University, Atlanta, Georgia, USA.
Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, USA.
Microbiol Spectr. 2024 Feb 6;12(2):e0350823. doi: 10.1128/spectrum.03508-23. Epub 2024 Jan 18.
Trace elements are associated with the microbial degradation of organic matter and methanogenesis, as enzymes in metabolic pathways often employ trace elements as essential cofactors. However, only a few studies investigated the effects of trace elements on the metabolic activity of microbial communities associated with biogenic coalbed methane production. We aimed to determine the effects of strategically selected trace elements on structure and function of active bacterial and methanogenic communities to stimulate methane production in subsurface coalbeds. Microcosms were established with produced water and coal from coalbed methane wells located in the Powder River Basin, Wyoming, USA. In initial pilot experiments with eight different trace elements, individual amendments of Co, Cu, and Mo lead to significantly higher methane production. Transcript levels of , the key marker gene for methanogenesis, positively correlated with increased methane production. Phylogenetic analysis of the cDNA library demonstrated compositional shifts of the active methanogenic community and increase of their diversity, particularly of hydrogenotrophic methanogens. High-throughput sequencing of cDNA obtained from 16S rRNA demonstrated active and abundant bacterial groups in response to trace element amendments. Active members increased in response to Co, Cu, and Mo additions. The findings of this study yield new insights into the importance of essential trace elements on the metabolic activity of microbial communities involved in subsurface coalbed methane and provide a better understanding of how microbial community composition is shaped by trace elements.IMPORTANCEMicrobial life in the deep subsurface of coal beds is limited by nutrient replenishment. While coal bed microbial communities are surrounded by carbon sources, we hypothesized that other nutrients such as trace elements needed as cofactors for enzymes are missing. Amendment of selected trace elements resulted in compositional shifts of the active methanogenic and bacterial communities and correlated with higher transcript levels of . The findings of this study yield new insights to not only identify possible limitations of microbes by replenishment of trace elements within their specific hydrological placement but also into the importance of essential trace elements for the metabolic activity of microbial communities involved in subsurface coalbed methane production and provides a better understanding of how microbial community composition is shaped by trace elements. Furthermore, this finding might help to revive already spent coal bed methane well systems with the ultimate goal to stimulate methane production.
微量元素与有机质的微生物降解和产甲烷作用有关，因为代谢途径中的酶通常将微量元素用作必需的辅助因子。然而，只有少数研究调查了微量元素对与生物成因煤层甲烷生产相关的微生物群落代谢活性的影响。我们的目的是确定战略性选择的微量元素对活跃细菌和产甲烷群落的结构和功能的影响，以刺激地下煤层中的甲烷生成。微宇宙是用来自怀俄明州粉河盆地煤层气井的产出水和煤建立的。在最初的八项不同微量元素的试点实验中，钴、铜和钼的单独添加导致甲烷产量显著增加。产甲烷的关键标记基因 的转录水平与甲烷产量的增加呈正相关。 cDNA 文库的系统发育分析表明，活跃的产甲烷群落的组成发生了变化，其多样性增加，特别是氢营养型产甲烷菌的多样性增加。从 cDNA 获得的 16S rRNA 的高通量测序表明，对微量元素添加有反应的活跃细菌群。对 Co、Cu 和 Mo 添加的响应增加了 成员。这项研究的结果提供了关于必需微量元素对参与地下煤层甲烷的微生物群落代谢活性的重要性的新见解，并更好地了解微量元素如何塑造微生物群落组成。
重要性
煤层深部微生物的生命受到营养物质补充的限制。虽然煤层微生物群落周围都是碳源，但我们假设其他营养物质，如作为酶辅助因子所需的微量元素，也会缺失。选定微量元素的添加导致活跃的产甲烷和细菌群落的组成发生变化，并与更高的 转录水平相关。这项研究的结果不仅为通过在特定水文位置内补充微生物所需的微量元素来识别微生物的可能限制提供了新的见解，而且为微量元素对参与地下煤层甲烷生产的微生物群落代谢活性的重要性提供了新的见解，并更好地了解微量元素如何塑造微生物群落组成。此外，这一发现可能有助于恢复已经耗尽的煤层气井系统，最终目标是刺激甲烷生成。
