Microbial roles equivalent to geological agents of high temperature and pressure in deep Earth  

作　　者：XIE ShuCheng LIU Deng QIU Xuan HUANG XianYu Thomas J.ALGEO 

机构地区：[1]State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences [2]Laboratory of Critical Zone Evolution, School of Earth Sciences, China University of Geosciences [3]State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences [4]Department of Geology, University of Cincinnati

出　　处：《Science China Earth Sciences》2016年第11期2098-2104,共7页中国科学（地球科学英文版）

基　　金：supported by National Natural Science Foundation of China (Grant No. 41330103);the "111 Project" (Grant No. B08030)

摘　　要：Microbes not only show sensitive responses to environmental changes but also play important roles in geochemical and geophysical systems. It is well known that microbes have caused major changes in surface environments and biogeochemical cycles through Earth history. Microbial processes can also induce the synthesis of certain minerals under Earth-surface conditions that previously were believed to form only under high temperatures and pressures in the deep Earth. For example, microbes can promote the conversion of smectite to illite, synthesis of authigenic plagioclase, precipitation of dolomite, and biotransformation of geolipids. These effects of microbes are due to their large surface/volume ratios, enzyme production, and abundant functional groups. Microbial catalyzation of chemical reactions proceeds through reaction-specific enzymes, a decrease in Gibbs' s free energy, and/or break through the dynamics reaction thresholds via their metabolisms and physiology. Microbes can lower the surface free energy of mineral nuclei via biophysical adsorption due to their large surface/volume ratios and abundant functional groups. The mineral precipitation and transformation processes induced by microbes are functionally equivalent to geological processes operating at high temperatures and pressures in the deep Earth, suggesting that microbial processes can serve as analogs to deep abiotic processes that are difficult to observe.Microbes not only show sensitive responses to environmental changes but also play important roles in geochemical and geophysical systems. It is well known that microbes have caused major changes in surface environments and biogeochemical cycles through Earth history. Microbial processes can also induce the synthesis of certain minerals under Earth-surface conditions that previously were believed to form only under high temperatures and pressures in the deep Earth. For example, microbes can promote the conversion of smectite to illite, synthesis of authigenic plagioclase, precipitation of dolomite, and biotransformation of geolipids. These effects of microbes are due to their large surface/volume ratios, enzyme production, and abundant functional groups. Microbial catalyzation of chemical reactions proceeds through reaction-specific enzymes, a decrease in Gibbs＇ s free energy, and/or break through the dynamics reaction thresholds via their metabolisms and physiology. Microbes can lower the surface free energy of mineral nuclei via biophysical adsorption due to their large surface/volume ratios and abundant functional groups. The mineral precipitation and transformation processes induced by microbes are functionally equivalent to geological processes operating at high temperatures and pressures in the deep Earth, suggesting that microbial processes can serve as analogs to deep abiotic processes that are difficult to observe.

关 键 词：Geobiology Microbial functional groups Illitization Plagioclase Dolomite Geolipids 

分 类 号：P593[天文地球—地球化学]