Regulation of carbon cycling by microbial biomineralization processes in the ocean

Heterotrophic bacteria are fundamental components of marine ecosystems and play vital ecological roles in affecting energy flowing and carbon cycling. Previous studies of microbial carbon pump (MCP) have shown that heterotrophic bacteria can mediate the transformation of marine labile dissolved organic carbon (DOC) to refractory DOC (RDOC). The RDOC and other byproducts produced by bacterial metabolism can act as nucleation sites of calcium carbonate crystals, meanwhile alkalinity of the seawater can increase due to bacterial metabolism, both of which promote the precipitation of calcium carbonate in the ocean. However, the understanding of mechanism of microbial biomineralization is still constrained. To fill the gap, we isolated several mineralizing bacteria from coral ecosystems and illustrated that arginine maybe the important regulator of microbial biomineralization although the deeper learning was needed. Our study could potentially advance the understanding of microbial biomineralization and reveal the synergistic mechanism of MCP and carbonate counter pump (CCP).