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

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