Li Runjie, Liu Xiaolei, Wu Geng, Li Gaoyuan, Chen Jing-Hua, Jiang Hongchen, Dong Hailiang
Center for Geomicrobiology and Biogeochemistry Research, State Key Laboratory of Geomicrobiology and Environmental Changes, China University of Geosciences (Beijing), Beijing 100083, China.
School of Water Resources and Environment, China University of Geosciences (Beijing), Beijing 100083, China.
Sci Adv. 2025 Apr 18;11(16):eadu7080. doi: 10.1126/sciadv.adu7080.
Anoxygenic phototrophic sulfur bacteria flourish in contemporary and ancient euxinic environments, driving the biogeochemical cycles of carbon and sulfur. However, it is unclear how these strict anaerobes meet their high demand for iron in iron-depleted environments. Here, we report that pyrite, a widespread and highly stable iron sulfide mineral in anoxic, low-temperature environments, can support the growth and metabolic activity of anoxygenic phototrophic sulfur bacteria by serving as the sole iron source under iron-depleted conditions. Transcriptomic and proteomic analyses revealed that pyrite addition substantially up-regulated genes and protein expression involved in photosynthesis, sulfur metabolism, and biosynthesis of organics. Anoxic microbial oxidation of pyritic sulfur and consequent destabilization of the pyrite structure were postulated to facilitate microbial iron acquisition. These findings advance our understanding of the survival strategies of anaerobes in iron-depleted environments and are important for revealing the previously underappreciated bioavailability of pyritic iron in anoxic environments and anoxic weathering of pyrite.
无氧光合硫细菌在现代和古代的缺氧环境中大量繁殖，推动着碳和硫的生物地球化学循环。然而，尚不清楚这些严格厌氧菌在缺铁环境中如何满足其对铁的高需求。在此，我们报告，黄铁矿是缺氧、低温环境中广泛存在且高度稳定的硫化铁矿物，在缺铁条件下可作为唯一铁源支持无氧光合硫细菌的生长和代谢活性。转录组学和蛋白质组学分析表明，添加黄铁矿显著上调了参与光合作用、硫代谢和有机物生物合成的基因和蛋白质表达。推测黄铁矿硫的缺氧微生物氧化以及随之而来的黄铁矿结构不稳定有助于微生物获取铁。这些发现推进了我们对缺铁环境中厌氧菌生存策略的理解，对于揭示缺氧环境中黄铁矿铁此前未被充分认识的生物可利用性以及黄铁矿的缺氧风化具有重要意义。
