Precipitation of High Mg-Calcite and Protodolomite Using Dead Biomass of Aerobic Halophilic Bacteria  

作　　者：Qigao Fan Deng Liu Dominic Papineau Xuan Qiu Hongmei Wang Zhenbing She Linduo Zhao 

机构地区：[1]State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China [2]School of Environmental Studies,China University of Geosciences,Wuhan 430078,China [3]London Centre for Nanotechnology,University College London and Birkbeck College London,London 17-19,UK [4]Department of Earth Sciences,University College London,London WC1E 6BT,UK [5]Center for Planetary Sciences,University College London,London WC1E 6BT,UK [6]Illinois Sustainable Technology Center,Prairie Research Institute,University of Illinois at Urbana-Champaign,Champaign 61820,USA

出　　处：《Journal of Earth Science》2023年第2期456-466,共11页地球科学学刊（英文版）

基　　金：jointly supported by the National Natural Science Foundation of China(Nos.42272046,42072336 and 41772362);the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB26000000);the 111 Project of China(No.BP0820004);the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(No.CUGCJ1703)。

摘　　要：The microbial dolomite model has been used to interpret the origin of sedimentary dolomite.In this model,the formation of low-temperature protodolomite,an important precursor to sedimentary dolomite,can be facilitated either by actively metabolizing cells of anaerobic microbes and aerobic halophilic archaea or by their inactive biomass.Aerobic halophilic bacteria are widely distributed in(proto-)dolomite-depositing evaporitic environments and their biomass might serve as a template for the crystallization of protodolomite.To test this hypothesis,carbonation experiments were conducted using dead biomass of an aerobic halophilic bacterium(Exiguobacterium sp.strain JBHLT-3).Our results show that dead biomass of JBHLT-3 can accelerate Mg2+uptake in carbonate mineral precipitates.In addition,the amount of Mg incorporated into Ca-Mg carbonates is proportional to the concentration of biomass.High Mg-calcite is produced with 0.25 or 0.5 g/L biomass,whereas protodolomite forms with 1 g/L biomass.This is confirmed by the main Raman peak of Ca-Mg carbonates,which shifts towards higher wavenumbers with increased Mg substitution.Microbial cells and their imprints are preserved on the surface of high Mg-calcite and protodolomite.Hence,this study furthers our understanding of the dolomitization within buried and dead microbial mats,which provides useful insights into the origin of ancient dolomite.

关 键 词：protodolomite high Mg-calcite Mg-hydration effect microbial dead biomass BIOSIGNATURE PALEOBIOLOGY 

分 类 号：Q913[天文地球—古生物学与地层学] P578.61[生物学—古生物学]