Homogeneous Precipitation of Calcium Carbonates by Enzyme Catalyzed Reaction

A Biomimetic Nano-Scale Aggregation Route for the Formation of Submicron-Size Colloidal Calcite Particles

“…The processes of formation of bio-inorganic phases in biological systems are complex mechanisms that, almost as a rule, are characterized by several simultaneous events. An example of the complexity and of the importance of aggregation processes in the bioinspired formation of calcium carbonate in simplified, laboratory conditions can be found in previously reported cases dealing with the role of catalytically active ureases (Sondi & Matijević, 2001;Sondi & Salopek-Sondi, 2004;Škapin & Sondi, 2005). This unique process of the biomimetic precipitation of uniform nanostructured colloidal calcite additionally explains the precipitation process based on the aggregation of preformed nanosize particles (Sondi et al, 2008).…”

“…Recently, a new class of additives was used, the doublehydrophilic block copolymers, for the effective control of the morphogenesis of inorganic precipitates in aqueous solutions, offering the possibility to obtain solids of uncommon morphologies (Sedlak & Cölfen, 2001;Cölfen, 2006). Recently, following the protein templating concept, significant progress in the study of the bioinspired formation of calcium carbonates was accomplished through the use of catalytically active proteins, such as urease enzymes (Sondi & Matijević, 2001;Sondi & Salopek-Sondi, 2004). It was shown that during the homogeneous precipitation of carbonate solids by the urease-catalyzed reactions in aqueous solutions of calcium salts, nanosize calcite particles appeared during the early stages of the precipitation process.…”

“…Urease, generated by certain pathogenic bacteria, during urinary tract infections, plays a significant role in the formation of intracellular urinary stones (Edinliljegren et al, 1994). Recently, it was demonstrated that calcium carbonate polymorphs of different sizes and shapes can be obtained by homogeneous precipitation in solutions of calcium salts through the enzyme-catalyzed decomposition of urea by urease (Sondi & Matijević, 2001;Sondi & Salopek-Sondi, 2004). The role of urease in the formation of strontium and barium carbonates and their mixed compounds was also investigated (Sondi & Matijević, 2003;Škapin & Sondi, 2005).…”

“…However, this finding has long remained neglected. Recently, it has been theoretically and experimentally established that many colloids, prepared by precipitation from homogeneous solutions, are built up of nanosize subunits (Nakayama et al, 1995;Privman et al, 1999;Sondi & Matijević, 2001;. Therefore, this mechanism was shown to be quite common in the formation of colloidal particles that show www.intechopen.com A Biomimetic Nano-Scale Aggregation Route for the Formation of Submicron-Size Colloidal Calcite Particles 247 crystalline characteristics.…”

Enzyme-mediated synthesis of ceramic materials

“…Sondi et al 27), 30) reported that urease-mediated CaCO 3 precipitated in the amorphous phase at first, and spontaneously transformed to calcite via vaterite, while the morphology of urease-mediated SrCO 3 spontaneously evolved from spherical to rod-like. De la Rica and Matsui 40) reported that, on addition of zinc nitrate hexahydrate solution to a urease/urea solution, particles with a urease-core and a ZnO-shell, 18 nm in diameter, precipitated at room temperature (Fig.…”