Hall N, Wong W W, Lappan R, Ricci F, Jeppe K J, Glud R N, Kawaichi S, Rotaru A-E, Greening C, Cook P L M
Water Studies, School of Chemistry, Monash University, Melbourne, Victoria Australia.
Department of Microbiology, Biomedicine Discovery Institute, Monash University, Melbourne, Victoria Australia.
Nat Geosci. 2025;18(9):854-861. doi: 10.1038/s41561-025-01768-3. Epub 2025 Aug 7.
Methanogenesis is thought to be limited to strictly anoxic environments. While oxygenated oceans are a known methane source, it is argued that methane production is driven by methylphosphonate-degrading bacteria and potentially other sources rather than by methanogenic archaea. Here we develop in situ monitoring and ex situ manipulation experiments, combined with biogeochemical, metagenomic and culture-based experiments, to show that methane is rapidly produced by archaea in frequently oxygenated sandy sediments. We show that methane emissions from sandy sediments are not inhibited by repeated oxygen exposure and suggest the activity is driven by aerotolerant methylotrophic methanogens (primarily Methanosarcinaceae) broadly distributed in the surface layers of sandy sediments. Moreover, we show that methane emissions are driven by methylated seaweed and seagrass metabolites, revealing a feedback loop between primary production and greenhouse gas emissions.
甲烷生成被认为仅限于严格缺氧的环境。虽然含氧海洋是已知的甲烷来源，但有人认为甲烷的产生是由降解甲基膦酸盐的细菌以及潜在的其他来源驱动的，而不是由产甲烷古菌驱动的。在这里，我们开展了原位监测和异位操纵实验，并结合生物地球化学、宏基因组学和基于培养的实验，以表明在频繁含氧的沙质沉积物中，古菌能快速产生甲烷。我们表明，沙质沉积物中的甲烷排放不会因反复暴露于氧气而受到抑制，并表明该活动是由广泛分布于沙质沉积物表层的耐氧甲基营养型产甲烷菌（主要是甲烷八叠球菌科）驱动的。此外，我们表明甲烷排放是由甲基化的海藻和海草代谢产物驱动的，揭示了初级生产与温室气体排放之间的反馈回路。
