近日，中国农业和农村事务部沼气研究所承磊团队报道了单株古菌将长链脂肪酸氧化与产甲烷作用相偶联。这一研究成果于2026年10月21日发表在国际顶尖学术期刊《自然》上。

复杂有机化合物厌氧降解为甲烷和二氧化碳的过程在深部地下生物圈中很常见，长期以来被认为需要互养合作，而产甲烷菌则被局限于终末利用简单的C1和C2底物。热力学考虑、多组学分析和微宇宙实验表明，古菌谱系能够对复杂底物进行产甲烷降解。然而，纯培养中的实验验证仍然缺乏。

研究组报道，从中国一个石油储层中分离出一株嗜热古菌Methanoglobus dolicholipophagus AA-75，隶属于古藻门。菌株AA-75不仅将甲醇转化为甲烷、二氧化碳和乙酸，还利用从C7:0到C18:0的饱和脂肪酸以及包括C16:1、C18:1和C18:2在内的不饱和脂肪酸产生甲烷。研究组将后者称为脂营养型产甲烷作用，它整合了脂肪酸的β-氧化、Wood–Ljungdahl途径、经典的甲基四氢甲烷蝶呤：辅酶M甲基转移酶和甲基辅酶M还原酶复合体，以及一个细胞内电子传递系统。

一个甲醛-甲醇分支可能是产甲烷过程中C1代谢的辅助途径。由硬脂酸产生的甲烷具有中等程度的¹³C富集（δ¹³C–CH₄ = −40.0‰至−36.3‰），这不同于经典产甲烷途径所特有的强烈¹³C亏损。这些发现表明，产甲烷菌可以作为复杂有机物的初级降解者发挥作用，挑战了经典的互养范式，并呼吁对当前深部地下生物圈碳循环模型进行修正。

附：英文原文

Title: A single archaeon couples long-chain fatty acid oxidation to methanogenesis

Author: Yi, Yue, Cao, Zuorong, Wu, Kejia, Ding, Hengwu, Fu, Lin, Gao, Wenyi, Li, Ling, Zhou, Lei, Zhou, Zhuo, Dai, Lirong, Lu, Yahai, Cheng, Lei

Issue&Volume: 2026-10-21

Abstract: Anaerobic degradation of complex organic compounds to methane and carbon dioxide is common in the deep subsurface biosphere and has long been considered to require syntrophic cooperation, with methanogens confined to the terminal use of simple C1 and C2 substrates. Thermodynamic considerations, multi-omics analyses and microcosm experiments suggest that archaeal lineages are capable of methanogenic degradation of complex substrates1,2,3,4,5,6. However, experimental validation in pure culture was lacking. Here we report the isolation of a thermophilic archaeon, Methanoglobus dolicholipophagus AA-75, affiliated with Archaeoglobi, from a Chinese petroleum reservoir. Strain AA-75 not only converts methanol into methane, carbon dioxide and acetate, but also uses saturated fatty acids varying from C7:0 to C18:0 and unsaturated fatty acids including C16:1, C18:1 and C18:2 to produce methane. We term the latter lipotrophic methanogenesis, which integrates β-oxidation of fatty acids with the Wood–Ljungdahl pathway and the canonical methyl-tetrahydromethanopterin:coenzyme M methyltransferase and methyl-coenzyme M reductase complexes, together with an intracellular electron transfer system. A formaldehyde-methanol branch probably functions as an auxiliary route for C1 metabolism during methanogenesis. Methane produced from stearate is moderately 13C-enriched (δ13C–CH4=40.0‰ to 36.3‰), distinct from the strong 13C depletion characteristic of canonical methanogenic pathways. These findings demonstrate that methanogens can function as primary degraders of complex organic matter, challenging the classical syntrophic paradigm and calling for refinement of current models of carbon cycling in the deep subsurface biosphere.

DOI: 10.1038/s41586-026-11207-x

Source: https://www.nature.com/articles/s41586-026-11207-x