Department of Biology, Appalachian State University, 572 Rivers Street, Boone, NC 28608, USA.
Vale Living with Lakes Centre and the Department of Biology, Laurentian University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada.
FEMS Microbiol Lett. 2021 Dec 24;368(21-24). doi: 10.1093/femsle/fnab151.
Peatlands both accumulate carbon and release methane, but their broad range in environmental conditions means that the diversity of microorganisms responsible for carbon cycling is still uncertain. Here, we describe a community analysis of methanogenic archaea responsible for methane production in 17 peatlands from 36 to 53 N latitude across the eastern half of North America, including three metal-contaminated sites. Methanogenic community structure was analysed through Illumina amplicon sequencing of the mcrA gene. Whether metal-contaminated sites were included or not, metal concentrations in peat were a primary driver of methanogenic community composition, particularly nickel, a trace element required in the F430 cofactor in methyl-coenzyme M reductase that is also toxic at high concentrations. Copper was also a strong predictor, likely due to inhibition at toxic levels and/or to cooccurrence with nickel, since copper enzymes are not known to be present in anaerobic archaea. The methanogenic groups Methanocellales and Methanosarcinales were prevalent in peatlands with low nickel concentrations, while Methanomicrobiales and Methanomassiliicoccales were abundant in peatlands with higher nickel concentrations. Results suggest that peat-associated trace metals are predictors of methanogenic communities in peatlands.
泥炭地既可以积累碳，也可以释放甲烷，但由于其环境条件广泛，负责碳循环的微生物多样性仍不确定。在这里，我们描述了对 17 个来自北美东部 36 到 53 北纬地区的泥炭地中负责甲烷生成的产甲烷古菌群落的分析，其中包括三个受金属污染的地点。通过 Illumina 扩增子测序 mcrA 基因分析了产甲烷菌群落结构。无论是否包括受金属污染的地点，泥炭中的金属浓度都是产甲烷菌群落组成的主要驱动因素，特别是镍，它是甲基辅酶 M 还原酶中 F430 辅酶所必需的微量元素，但在高浓度下也具有毒性。铜也是一个强有力的预测因子，这可能是由于在有毒水平下的抑制作用，或者是由于与镍的共同存在，因为已知在厌氧古菌中不存在铜酶。在镍浓度较低的泥炭地中，产甲烷菌目和产甲烷菌科较为普遍，而在镍浓度较高的泥炭地中，产甲烷菌目和产甲烷菌科则较为丰富。研究结果表明，与泥炭相关的痕量金属是泥炭地中产甲烷菌群落的预测因子。
