Characterization and Stability of Calcium Carbonate Mineral Induced by Synechococcus sp. PCC 7942

Investigating the stability of microbially induced aragonite and vaterite is crucial for elucidating the phase transformation mechanisms of biogenic carbonate minerals. Although previous studies have demonstrated the stability of biogenic vaterite, the stability of binary or ternary mineral assemblages has not yet been reported. In this study, carbonate minerals (calcite–aragonite and vaterite–calcite–aragonite assemblages) precipitated by Synechococcus sp. PCC 7942 were subjected to 300-day aging experiments under ambient air conditions to investigate the stability and characteristics of biogenic aragonite and vaterite. The results revealed that vaterite and aragonite induced by strain PCC 7942 remained stable for a longer period than their chemically synthesized counterparts, which is potentially attributable to the presence of organic matter that inhibits phase transformation. Nevertheless, these biogenic CaCO3 phases ultimately transformed into calcite via a dissolution-reprecipitation mechanism over the 300-day aging period. These findings provide significant insights into phase transformation pathways and the long-term stability of carbonate minerals in terrestrial environments. Show that characterization and stability of binary or ternary mineral phase mixtures induced by Synechococcus sp. PCC7942 in air; Elevated organic matters enhanced the stabilization of vaterite and aragonite; Propose that potential transformation pathways of carbonate minerals induced by Synechococcus sp. PCC7942.