The effect of Bacillus cereus LV-1 on the crystallization and polymorphs of calcium carbonate

Abstract

The study of CaCO3 polymorphism is of great significance for understanding the mechanism of bacterial carbonate mineralization and the genesis of carbonate rock formation throughout geological history.

Structure Evolution of CaCO3 Precipitates Formed during the Bacillus cereus Induced Biomineralization

“…Tobler et al showed that an increase in pH contributes to the stabilization of ACC, slowing down the crystallization process and the passage of the vaterite phase in which ACC crystallizes into calcite [30]. In a bacterial environment, the polymorphic transition of CaCO 3 takes many hours and occurs at significantly lower pH values (about 7.5 [16,31]). Such stabilization may be explained by the presence of organic inclusions (polysaccharides, eDNA or amyloids) in the extracellular matrix, since the stabilizing role of some macromolecules such as polyaspartic acid, polyethylene glycol and dendrimers was demonstrated in the in vitro system [32], as was stabilization by protein structures for the system in vivo [33].…”

“…To the best of our knowledge, there are no studies of the nano-and meso-sized structures of polymorphs formed during calcium carbonate crystallization or polymorphic transitions in a system containing bacterial cells. However, there are a large number of publications in which the chemical composition of precipitates formed during biomineralization process was characterized by various methods, mainly IR spectroscopy [35][36][37], XRD [31,[34][35][36][37][38], SEM, FIB and EDX [31,34]. The above methods were frequently used to describe the morphology [31,34,36] and polymorphic composition of crystals [31,[34][35][36]), which varied in different types of bacteria.…”

“…However, there are a large number of publications in which the chemical composition of precipitates formed during biomineralization process was characterized by various methods, mainly IR spectroscopy [35][36][37], XRD [31,[34][35][36][37][38], SEM, FIB and EDX [31,34]. The above methods were frequently used to describe the morphology [31,34,36] and polymorphic composition of crystals [31,[34][35][36]), which varied in different types of bacteria. These might include, besides the widespread phases (vaterite, ACC and calcite), rare aragonite and hydrated crystalline phases of monohydrocalcite, hexahydrocalcite or even ikaite not commonly observed in the in vitro system but occurring in nature [20].…”