Synthesis and characterization of calcium carbonate on three kinds of microbial cells templates

Abstract As is known, the formation of nanocrystals is influenced by the cells with which they interact. In particular, the same materials could exhibit different properties depending on the type of cells. In this work, we used three different types of microbial cells (Escherichia coli, Staphylococcus aureus, and Beer Yeast) as biological templates to control the crystallization of calcium carbonate particles before or after coated with several layers of polyelectrolyte films via Layer-by-Layer assembly and biomineralization process. The results showed that the resulting crystal types using different naked cells as templates all include calcite and vaterite, and the ratio of vaterite is higher. After encapsulating with polyelectrolyte, polyelectrolyte did not change the ratio of calcite to vaterite on the surface of E. coli and Staphylococcus aureus but yeast. Furthermore, it can weaken the intensity of vaterite and increase the proportion of calcite using the yeast as template. Differences in calcium carbonate crystal forms are related to the differences in cell wall components and cell secretion. So we mineralized calcium carbonate with the main components of the yeast cell wall (mannose oligosaccharide, β-glucan) and the Gram bacterial wall (peptidoglycan, lipopolysaccharide) directly, it was found that the composition of the cell wall did affect the crystal form and morphology of the calcium carbonate. This provides a reference for further study of the biomineralization mechanism and the selection of mineralization templates. Furthermore, this study provides some supplementary for understanding the natural mineralization process of CaCO3.