Microbial imprints on sulfide minerals in submarine hydrothermal deposits

Diverse numbers of iron- and sulfur-oxidizing microbes have been found in submarine hydrothermal deposits. They have played a prominent role in weathering of seafloor sulfide deposits. However, evidence for microbe-mineral interactions in sediments is rare. Mineralogic analysis and scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDX) examination of sulfide deposits from the East Pacific Rise demonstrated that (1) sulfide minerals were extensively leached, with characteristic microbial dissolution pits on mineral surfaces; (2) the possible <i>Acidithiobacillus</i>-like bacteria and metabolites were found closely associated with the dissolution pits <i>in situ</i>. The results provide direct evidence for microbial leaching on the solid mineral crystals, most likely by the contact mechanisms, in the seafloor sulfide deposits.

研究在海底热液沉积物中发现了多种铁、硫氧化微生物，它们在海底硫化物矿床的风化过程中发挥了重要作用。然而，目前关于沉积物中微生物-矿物相互作用的直接证据仍较为匮乏。对东太平洋海隆硫化物矿床开展的矿物学分析、扫描电子显微镜-能量色散X射线光谱（SEM-EDX）检测结果显示：其一，硫化物矿物已被广泛淋溶，矿物表面可见典型的微生物溶蚀坑；其二，在溶蚀坑原位处发现了疑似嗜酸硫杆菌属（Acidithiobacillus）的细菌及其代谢产物，二者紧密结合。该研究结果为海底硫化物矿床中固体矿物晶体的微生物淋溶作用提供了直接证据，且该过程极有可能通过接触机制实现。