Dong Chuanqi, Han Xiqiu, Wang Yejian, Liu Jiqiang, Wei Mingcong
College of Marine Geosciences, Ocean University of China, Qingdao 266100, China.
State Key Laboratory of Submarine Geoscience, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China.
Biology (Basel). 2025 Apr 9;14(4):389. doi: 10.3390/biology14040389.
The weathering of seafloor hydrothermal sulfides is facilitated by microbial activities, yet the specific mechanisms of different sulfide types are not well understood. Previous studies have primarily been carried out under laboratory conditions, making it difficult to accurately replicate the complex in situ conditions of deep-sea hydrothermal fields. Herein, we deployed two well-characterized pyrite (Py)-dominated and chalcopyrite (Ccp)-dominated sulfide slices, which were placed 300 m from an active venting site in the Wocan-1 hydrothermal field (Carlsberg Ridge, Northwest Indian Ocean) for an 18-month in situ incubation experiment. Microscopic observations and organic matter analyses were conducted on the recovered sulfide slices to investigate the microbial weathering features of different sulfide types. Our results demonstrated that the weathering of the Py-dominated sulfide sample was primarily mediated by extracellular polymeric substances (EPSs) through indirect interactions, whereas the Ccp-dominated sulfide sample exhibited both direct microbial dissolution, resulting in the formation of distinct dissolution pits, and indirect EPS-mediated interactions. Four distinct phases of microbe-sulfide interactions were identified: approach, adsorption, stable attachment, and extensive colonization. Furthermore, the weathering products and biomineralization structures differed significantly between the two sulfide types, reflecting their different microbial colonization processes. Our study confirms that microorganisms are crucial in seafloor sulfide weathering. These findings advance our understanding of microbial-driven processes in sulfide mineral transformations and their role in marine ecosystems. Our findings are also valuable for future research on biogeochemical cycles and for developing bioremediation strategies for deep-sea mining.
海底热液硫化物的风化作用受微生物活动的促进，但不同硫化物类型的具体机制尚不清楚。以往的研究主要在实验室条件下进行，难以准确复制深海热液区复杂的原位条件。在此，我们部署了两片特征明确的以黄铁矿（Py）为主和以黄铜矿（Ccp）为主的硫化物切片，将其放置在沃坎 - 1热液区（印度洋西北部卡尔斯伯格海岭）一个活跃喷口位点300米处，进行了为期18个月的原位培养实验。对回收的硫化物切片进行了显微镜观察和有机质分析，以研究不同硫化物类型的微生物风化特征。我们的结果表明，以Py为主的硫化物样品的风化主要由细胞外聚合物（EPSs）通过间接相互作用介导，而以Ccp为主的硫化物样品既表现出直接的微生物溶解，形成明显的溶解坑，也表现出间接的EPS介导的相互作用。确定了微生物与硫化物相互作用的四个不同阶段：接近、吸附、稳定附着和广泛定殖。此外，两种硫化物类型的风化产物和生物矿化结构存在显著差异，反映了它们不同的微生物定殖过程。我们的研究证实微生物在海底硫化物风化中至关重要。这些发现推进了我们对硫化物矿物转化中微生物驱动过程及其在海洋生态系统中作用的理解。我们的发现对于未来生物地球化学循环研究以及开发深海采矿的生物修复策略也具有重要价值。
