近日，中国科学院大学东秀珠团队研究了缺氧泥炭地木质素产甲烷。该项研究成果发表在2025年8月13日出版的《自然—地球科学》杂志上。
木质素是一种天然植物聚合物，约占生物圈有机碳的三分之一。全球变暖导致了灌木的入侵和泥炭地木质素的增加。一般来说，木质素在缺氧环境中不易被微生物降解。
研究组报道了中国淹水泥炭地木质素及其单酚类化合物产生甲烷的微观实验。木质素含量较高的中等灌丛覆盖泥炭地土壤甲烷产量高于草本覆盖土壤。添加较低含量的木质素及其单酚促进了草本土壤微生物甲烷的产生，木质素对甲烷总排放量的贡献约为1.2 ~ 14.2%。同位素示踪和动态代谢组学分析表明，香兰素的甲氧基首先被转化为甲烷，然后芳香环碳被发酵成CO2、醋酸盐、丙酸盐和异丁酸盐。
木质素及其单体酚富集了甲基营养型产甲烷菌——甲烷球菌属（Methanomassiliicoccus）和甲烷八叠球菌属（Methanosarcina），表明它们参与了甲氧基营养型产甲烷作用。研究组认为在泥炭地中，木质素作为一种甲烷来源不应被忽视，尤其是在全球变暖背景的灌木持续扩张的情形下。
附：英文原文
Title: Methane production from lignin in anoxic peatland
Author: Liu, Tuo, Li, Lingyan, Xue, Kai, Wang, Xuemeng, Li, Huiju, Wang, Yanfen, Dong, Xiuzhu
Issue&Volume: 2025-08-13
Abstract: Lignin is a natural plant polymer that accounts for about one-third of the organic carbon in the biosphere. Global warming has led to shrub encroachment and increased lignin input into peatlands. Generally, lignin is recalcitrant to microbial degradation in anoxic environments. Here we report methane production from lignin and its constituent monophenols in a flooded peatland in China based on microcosm experiments. Methane production was higher in the moderate shrub-covered peatland soils that have greater lignin contents compared with those of herb-covered soils. Adding lower contents of lignin and its monophenols promoted methane production of herb soil microcosms, and lignin contributed approximately 1.2–14.2% of the total methane emissions. Isotope tracing and dynamic metabolomic analyses revealed that the methoxy group of vanillin was first converted to methane, and then the aromatic ring carbons were fermented into CO2, acetate, propionate and (iso)butyrate. Lignin and its monophenols enriched the methylotrophic methanogens Methanomassiliicoccus and Methanosarcina, suggesting their involvement in methoxydotrophic methanogenesis. We suggest that lignin should not be overlooked as a source of methane in peatlands, especially given increasing shrub encroachment under global warming.
DOI: 10.1038/s41561-025-01758-5
Source: https://www.nature.com/articles/s41561-025-01758-5