微生物成因的碳酸盐矿物研究进展

微生物诱导碳酸盐类矿物沉淀是地质微生物学的研究热点之一.微生物主要通过其代谢活动促进细胞周围微环境pH值及水体CO32-]的升高,最终表现为碳酸盐类矿物饱和指数的增加.此外,微生物及其分泌的胞外聚合物可作为碳酸盐晶核的成核位点,为碳酸盐矿物晶体的生长进一步提供有利条件.微生物成因与纯化学成因的碳酸盐类矿物相比具有不同的矿物特征(如形貌、微量元素含量及碳同位素等).深入了解微生物诱导碳酸钙沉淀的行为对理解地质时期微生物活动及其在二氧化碳的地质封存中的潜在应用具有指导意义.本文综述了微生物诱导碳酸盐矿物沉淀的机理、代谢过程,总结了该领域的最新进展,探讨了生物成因以及化学成因碳酸盐矿物的区别,最后指出了该项研究在微生物岩以及CO2地质封存上的一些可能的拓展方向.

Microbially induced carbonate precipitation: a review

Microbially induced carbonate formation has attracted much attention in the field of geomicrobiology. Microorganisms have been demonstrated to be effective agents to produce polymorphy carbonate minerals by enhancing pH and CO32? concentration, both of which are the essential factors controlling the saturation index of carbonate minerals. Furthermore, microorganisms themselves and the secreted extracellular polymeric substances can also facilitate carbonate precipitation via serving as nucleation sites for mineral growth. Compared with abiotic carbonate minerals, microbially induced carbonate exhibits special properties on mineral morphology, trace elements content and carbon isotope composition. Understanding of microbially induced carbonate and their special signatures is of unequivocal significance to probe the microbial activities throughout the earth history and provide application to geologic CO2 sequestration. Here we reviewed the latest progress on microbially induced carbonate precipitation, the related microbe metabolism processes and, the differences between biogenic and chemogenic carbonate, possible application of microbially induced carbonate on microbialite and CO2 sequestration were discussed finally.