A Review on Role of Bacillus Species in Bio-Calcification: A Way Forward in Carbonate Precipitation

Bio-calcification, also known as microbiologically induced calcite precipitation, is a phenomenon involving the activity of the enzyme urease. A large number of soil microorganism exhibit urease-producing ability. The main purpose of this review article is to signify the calcium carbonate bio-precipitation by Bacillus species including Lysinibacillus sphaericus and Bacillus subtilis. They both precipitated calcite and the shape and size depending on the external and internal conditions like the type of culture medium and the bacterial strains that were used. The research group increased attentions toward MICP (microbial-induced carbonated precipitation) because of its eco-friendly application. Different bacterial strains had been reported to be isolated that could precipitate carbonate. Many bio-calcifying bacterial strains related to Bacillus species had been reported from the deep sea. NIOTVJ5 has been reported to show urease and calcite crystals activity similar to Bacillus thuringiensis. That strain could live under extreme conditions like high pressure in deep-sea and produce strong monogenic biofilm. EM (Electron Microscopy) and depressive X-ray spectroscopy confirmed the presence of calcium carbonate. The bacteria need calcium lactate, which reacts with the calcium carbonate (CaCO3) and that process, is known as bio-calcification.