The molecular regulatory mechanisms of the bacteria involved in serpentine weathering coupled with carbonation

Development of an effective biotechnological method of reducing the continuous emission of CO2 has caused wide public concern. Research on serpentine bio-weathering coupled with carbonation is a current focus of interest. To investigate the molecular mechanisms, Bacillus subtilis was cultured in the Mg2+-free medium with the addition of serpentine. Based on the composition of organic matter and the characterization of the weathered serpentine, quantitative proteomics technology was adopted to elucidate the roles of proteins played in the coupled process. Electrochemical analysis and vapor diffusion crystallization experiments were also performed to reveal the molecular mechanisms. The results demonstrated that more oxidoreductases were secreted to facilitate the transformation of serpentine, and drive the synthesis of organic acids to accelerate the weathering of serpentine. In the late stage of serpentine weathering, that is, the serpentine carbonation stage, the characterization of the secondary minerals showed that struvite and amorphous carbonate had been formed with some organic matter. In serpentine carbonation stage, excessive Ni in the microenvironment drove N metabolism to facilitate the elevation of pH, resulting in the serpentine carbonation. This study enriched our understanding of the molecular mechanisms at protein-level in serpentine bio-weathering coupled with carbonation.