Biomimetic Mineralization of CaCO₃on a Phospholipid Monolayer: From an Amorphous Calcium Carbonate Precursor to Calcite via Vaterite

Abstract

A phospholipid monolayer, approximately half the bilayer structure of a biological membrane, can be regarded as an ideal model for investigating biomineralization on biological membranes. In this work on the biomimetic mineralization of CaCO(3) under a phospholipid monolayer, we show the initial heterogeneous nucleation of amorphous calcium carbonate precursor (ACC) nanoparticles at the air-water interface, their subsequent transformation into the metastable vaterite phase instead of the most thermodynamically stable calcite phase, and the ultimate phase transformation to calcite. Furthermore, the spontaneity of the transformation from vaterite to calcite was found to be closely related to the surface tension; high surface pressure could inhibit the process, highlighting the determinant of surface energy. To understand better the mechanisms for ACC formation and the transformation from ACC to vaterite and to calcite, in situ Brewster angle microscopy (BAM), ex situ scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and X-ray diffraction analysis were employed. This work has clarified the crystallization process of calcium carbonate under phospholipid monolayers and therefore may further our understanding of the biomineralization processes induced by cellular membranes.

Induced transformation of amorphous silica to cristobalite on bacterial surfaces

“…Examples of these molecules are amino acids, polysaccharide, and proteins. 36 Because we also observed that bacterial surface charge did not affect amorphous silica transformation, it is possible that the surface energy of phospholipid membranes promotes the phase transformation of amorphous silica. In the present study, the surfaces of both Gram-positive and -negative bacteria are observed to promote the transformation of amorphous silica.…”

Mineral CO2 sequestration by environmental biotechnological processes

“…The precipitation profile obtained by the ion activity product (Ca 2+ )(CO 3 2-), in the performed experiments with calciumacetate and starch (shown in Figs. 5.1a, 5.1c, 3a and 5.3c), suggests the common pattern of CaCO 3 precipitation with initial formation of less stable polymorphs and the subsequent ripening to the calcite precipitate (Gebauer & Cölfen, 2011;Xiao et al, 2009). Studying the type of CaCO 3 precipitate by comparing the ion activity product of Ca 2+ and CO 3 2-ions to the solubility products of the polymorphs were done in the previous studies as well (Gebauer & Cölfen, 2011;Lindeboom et al, 2013;Nehrke, 2007;Sawada, 1997).…”

Pseudomonas,PantoeaandCupriavidusisolates induce calcium carbonate precipitation for biorestoration of ornamental stone

“…Vaterite's transformation to the most stable calcite is inhibited by the incorporation of organic compounds that became entangled during precipitation (Xiao et al . ; Natoli et al . ) in close vicinity of the cells or from the cell wall itself.…”