Calcium carbonate precipitation and crystal morphology induced by microbial carbonic anhydrase and other biological factors

Abstract The effect of microbial carbonic anhydrase (CA) on the calcium carbonate (CaCO 3 ) precipitation was systematically investigated comparing to other biological factors (bovine CA, bovine serum albumin, carboxymethyl chitosan and glutamic acid). The results showed that the precipitation rate of Ca 2+ in the presence of either microbial CA or bovine CA was faster than that in the presence of 1% bovine serum albumin, 1% carboxymethyl chitosan or 1% glutamic acid, respectively. In addition, XRD analysis indicated that the dominant CaCO 3 crystal phase was calcite. The CaCO 3 crystal morphologies mainly showed cubic and polyhedral shapes induced by microbial CA, and became multiformity induced by other factors from FE-SEM analysis. These results suggested a novel approach for biomimetic synthesis of CaCO 3 materials by microbial CA.