EAGER: Are methylotrophic substrates important in northern peatland methane cycling?

泥炭地是许多北方景观中常见的一种湿地。这些生态系统在全球碳循环中发挥着重要作用。作为自然分解过程的结果，泥炭地向大气中贡献了很大一部分甲烷气体，并可能因环境条件的变化而释放更多的甲烷。我们目前对泥炭地甲烷动力学的理解建立在这样一个前提之上，即在自然生态系统中，甲烷是通过两种不同的微生物过程产生的。然而，有证据表明，甲烷产生的第三条途径被忽视了，这可能是重要的。利用现场测量和实验室实验相结合的方法，研究小组将调查在明尼苏达州泥炭地通过以前未被探索的途径产生的甲烷的潜在作用。这项研究还将提供培训本科生如何在查普曼大学进行研究的机会。这个热切的项目的中心目标是探索甲醇营养底物(如甲醇、单甲胺和二甲硫化物)作为北部泥炭地生态系统甲烷的重要来源的可能性。这个项目将解决明尼苏达州北部3个泥炭地的4个研究问题。(1)甲烷菌能处理甲基营养底物吗？为了研究甲烷通过甲基营养途径产生的可能性，研究人员将在实验室培养中使用13C标记的底物作为同位素示踪剂。(2)现场是否有甲基营养底物？研究人员将开发分析技术来测量泥炭地孔隙水中甲基营养底物的浓度。(3)在一个生长季节内，甲烷生成的速率是多少？研究人员将结合13C标记示踪剂产生的甲烷的测量和甲基营养底物的浓度来估计该项目第二年整个生长季的甲基营养甲烷生成率。(4)哪些微生物群落对甲基营养产甲烷负有责任？研究人员将分析可能导致甲基营养甲烷产生的微生物群落。鉴于泥炭地在全球碳循环中的重要性，对这些栖息地的甲烷循环有一个完整的机械理解是至关重要的。如果以前研究不足的甲基营养底物在泥炭地甲烷循环中很重要，那么就需要重新考虑从局部到全球范围内的碳循环模型。

Peatlands are a type of wetlands common in many northern landscapes. These ecosystems play an important role in the global carbon cycle. As a result of natural decomposition processes, peatlands contribute a significant fraction of methane gas to the atmosphere and could release additional methane in response to changes in environmental conditions. Our current understanding of peatland methane dynamics is built upon the premise that methane is produced through two different microbial processes in natural ecosystems. However, there is evidence that a third pathway of methane production has been overlooked, and could be important. Using a combination of field measurements and laboratory experiments, the research team will investigate the potential role of methane produced through the previously unexplored pathway in peatlands in Minnesota. This research will also provide opportunities to train undergraduate students how to do research at Chapman University, a primarily undergraduate institution.The central goal of this EAGER project is to explore the possibility that methylotrophic substrates (e.g., methanol, monomethylamine and dimethylsulfide) serve as important sources of methane in northern peatland ecosystems. This project will address 4 research questions in 3 peatlands in northern Minnesota. (1) Can methylotrophic substrates be processed by methanogens? To investigate the potential for methane production through methylotrophic pathways, the researchers will use 13C-labeled substrates as isotopic tracers in laboratory incubations. (2) Are methylotrophic substrates available in situ? The researchers will develop analytical techniques to measure concentrations of methylotrophic substrates in peatland porewater. (3) What are the rates of methylotrophic methanogenesis over a growing season? The researchers will combine measurements of methane production from 13C-labeled tracers and concentrations of methylotrophic substrates to estimate rates of methylotrophic methanogenesis across the growing season in the second year of this project. (4) What microbial communities are responsible for methylotrophic methanogenesis? The researchers will analyze the microbial communities potentially responsible for methylotrophic methane production. Given the importance of peatlands in the global carbon cycle, it is crucial to have a complete mechanistic understanding of methane cycling in these habitats. If previously understudied methylotrophic substrates are important in peatland methane cycling, it would require reconsideration of carbon cycle models at local to global scales.