The hidden role of heterotrophic bacteria in early carbonate diagenesis.

ABSTRACT: Microbial impacts on early carbonate diagenesis, particularly the formation of Mg-carbonates at low temperatures, have long eluded scientists. Our breakthrough laboratory experiments with two species of halophilic aerobic bacteria and marine carbonate grains reveal that these bacteria created a distinctive protodolomite (disordered dolomite) rim around the grains. Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) confirmed the protodolomite formation, while solid-state nuclear magnetic resonance (NMR) revealed bacterial interactions with carboxylated organic matter, such as extracellular polymeric substances (EPS). We observed a significant carbon isotope fractionation (average δ¹³C = 11.3‰) and notable changes in Mg/Ca ratios throughout the experiments. Initial med

SUBMITTER: Sanchez-Roman M 

PROVIDER: S-EPMC11696100 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature