当前位置: X-MOL 学术Soil Biol. Biochem. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Homoacetogenesis competes with hydrogenotrophic methanogenesis for substrates in a peatland experiencing ecosystem warming
Soil Biology and Biochemistry ( IF 9.7 ) Pub Date : 2022-06-18 , DOI: 10.1016/j.soilbio.2022.108759
Cory LeeWays , Laura L. McCullough , Anya M. Hopple , Jason K. Keller , Scott D. Bridgham

Peatlands contain up to half of terrestrial soil organic carbon (C) while simultaneously emitting the potent greenhouse gas methane (CH4). Global change will alter C biogeochemistry in peatlands, but is hard to predict without a mechanistic understanding of the processes that control anaerobic C cycling. One of the least known anaerobic C cycling pathways in wetland systems is homoacetogenesis, the reduction of carbon dioxide (CO2) with dihydrogen (H2) to acetate. We developed a new technique to infer rates of putative homoacetogenesis by measuring the incorporation of 14C-labeled dissolved inorganic C into dissolved organic matter. We determined rates of homoacetogenesis and total and hydrogenotrophic CH4 production throughout the peat profile on two sampling dates in a whole-ecosystem warming and elevated CO2 experiment in a northern Minnesota bog, USA. Homoacetogenesis and hydrogenotrophic CH4 production were greatest in surface soils and at warmer temperatures. However, homoacetogens were stronger competitors than hydrogenotrophic methanogens for H2 in deeper soil depths and at lower temperatures. A higher ratio of acetoclastic to hydrogenotrophic methanogenesis is often associated with greater total CH4 production, indicating that homoacetogenesis potentially can indirectly increase total CH4 production. Additionally, failure to account for homoacetogenesis may lead to erroneous conclusions in stable isotope models of anaerobic C cycling and CH4 production. This work shows that homoacetogenesis responds to warming and may impact CH4 production, and thus this process should be included in future modeling of climate change effects in wetlands.



中文翻译:

在经历生态系统变暖的泥炭地中,Homoacetogenesis 与氢营养产甲烷作用竞争底物

泥炭地含有多达一半的陆地土壤有机碳 (C),同时排放强效温室气体甲烷 (CH 4 )。全球变化将改变泥炭地的 C 生物地球化学,但如果不从机理上理解控制厌氧 C 循环的过程,就很难预测。湿地系统中最不为人知的厌氧 C 循环途径之一是同型乙酸生成,即用二氢 (H 2 ) 将二氧化碳 (CO 2 ) 还原为乙酸盐。我们开发了一种新技术,通过测量14 C 标记的溶解无机 C 掺入溶解有机物质中来推断假定的同型乙酸生成率。我们确定了同型乙酸生成和总和氢营养 CH 4的速率在美国明尼苏达州北部沼泽地的整个生态系统变暖和 CO 2升高实验中的两个采样日期,整个泥炭剖面的产量。Homoacetogenesis 和氢营养型 CH 4产量在表层土壤和较高温度下最多。然而,在较深的土壤深度和较低的温度下,对于 H 2来说,同型产乙酸菌比氢营养产甲烷菌更强。较高的乙酸分解与氢营养产甲烷的比例通常与较高的总 CH 4产量相关,这表明同型乙酸生成可能间接增加总 CH 4生产。此外,未能解释同型乙酸生成可能会导致在厌氧 C 循环和 CH 4产生的稳定同位素模型中得出错误的结论。这项工作表明,同型乙酸生成对变暖作出反应并可能影响 CH 4的产生,因此这一过程应包括在未来对湿地气候变化影响的建模中。

更新日期:2022-06-18
down
wechat
bug