Study on microbiological precipitation of CaCO₃

Taking advantage of enzyme digestion process occurred in the growth of carbonate-mineralization microbe of bacteria A, and by adding Ca²⁺ timely, orbicular CaCO₃ with diameter of less than 10 μm was precipitated successfully, which was proved to be calcite crystalloid through XRD analysis. The crystal shape of CaCO₃ and its granule figure would change to some extent when the environment reaction conditions (such as pH, temperature, source and consistency of Ca²⁺, etc). Besides, some contrastive experiments by using the artificially distilled alike vegetable enzyme were conducted, from which fine rhombohedron-shaped calcite was also obtained. It is verified that the key to the precipitation and mineralization of CaCO₃ is the enzyme digestion characteristics of carbonate-mineralization microbe.