微生物成矿

微生物对生命元素如碳、氮、硫、氧和金属离子的代谢作用能显著的改变微生物周边的外部环境和其内部环境。在一系列的生物地球化学过程中，微生物参与了矿产的沉积(生物成矿)或参与了矿石和岩石的溶解(生物风化)。生物成矿作用有两个途径：一个叫生物诱导成矿，通过这个过程，微生物分泌出代谢产物导致了之后的矿物颗粒的沉积；另一个叫生物控制成矿，在这个过程中，微生物在控制矿物成核和生长上起到了显著作用。微生物成因的矿物总体来说颗粒都很小和／或有着独特的同位素特征。最普遍的生物成因矿物有碳酸盐、硫化物和铁的氧化物。细胞表面和其分泌的胞外聚合物的结构可以为离子的浓缩、聚合和矿化提供模板，并起到重要作用。地球材料的仿生合成帮助我们了解了在人工条件下的生物成矿机制。此外，在地质环境中生物成因的矿物还可以作为一种生物信号，用来重建地球和其他行星的起源和演化。

Microbial Biomineralization

Microbial metabolism of life-essential elements such as carbon, nitrogen, sulfur, oxygen and metals can significantly change the physicochemical conditions of their external or internal environments. Through a variety of biogeochemical processes, microorganisms mediate the precipitation of minerals (biomineralization) or dissolution of minerals or rocks (microbial weathering). Biomineralization can have two pathways. One is called biological induced mineralization by which organisms secrete metabolic products that result in subsequent deposition of mineral particles; another pathway is called biologically controlled mineralization by which the microbes exert a significant degree of control over the nucleation and growth of the minerals. The minerals of microbial genesis are generally characterized by small grain size and/or unique isotopic features. The most common biogenetic minerals are carbonates, sulfides and iron oxides. The structure of cell surface and the exopolymers excreted plays an essential role in forming templates for ions to condense, assemble and mineralize. Biomimetic synthesis of Earth materials helps us to understand the mechanism of biomineralization under artificial conditions. Furthermore, biogenic minerals in geological environments can be used as biosignatures, which help to retrieve the origin and evolution of life on Earth and other planets.