Crustal faulting drives biological redox cycling in the deep subsurface

作者：Xiao Wu, Jianxi Zhu, Hongmei Yang, Yiping Yang, Xiaoju Lin, Xiaoliang Liang, Mang Lin, Barbara Sherwood Lollar, Kurt O. Konhauser, Hongping He · 发表于：Science Advances · 年份：2025 · DOI：10.1126/sciadv.adx5372 · 被引用次数：13 · 研究领域：Methane Hydrates and Related Phenomena、Microbial Fuel Cells and Bioremediation、Hydrocarbon exploration and reservoir analysis

In the deep biosphere, where surface-derived substrates are depleted, microbial communities rely on redox pairs generated through water-rock reactions to sustain metabolism. A notable example of this is the production of hydrogen gas (H 2 ) and oxidants from rock fracturing. However, the potential interactions between these initial redox pairs and a key subsurface element—iron (Fe)—remain underexplored. Here, we simulated radical-induced water splitting to investigate the formation and evolution of redox gradients. Our results show that in the presence of Fe, ferrous iron (Fe 2+ ) was marginally oxidized to ferric iron (Fe 3+ ) by low concentrations of oxidants, whereas Fe 3+ was efficiently reduced back to Fe 2+ by reactive hydrogen atoms (•H). We propose that crustal faulting can generate various redox pairs and drive Fe redox cycling, thereby providing a sustained energy source for subsurface life on Earth and potentially on other planetary bodies.