English

Abstract

Biomineralization is an important and ubiquitous process resulting in biominerals, produced by a range of taxa, from bacteria and to eukarya. Calcium carbonate precipitation was reported in many bacterial species, both in vivo and in vitro conditions which is influenced by various abiotic factors and could transform soluble organic nutrients into insoluble inorganic calcite crystals. Biologically controlled mineralization (BCM) of calcium carbonate involves a remarkable control in size, morphology and phase selection, resulting in complex hierarchical organic- inorganic structures with unusual physicochemical properties. The calcium carbonate thus secreted can be used in various applications and as an additive admixture in building materials. In this study calcareous bacteria were isolated from marine sediments, which were able to produce calcium carbonate crystals by utilizing organic and inorganic nitrogen source indicating the nitrogen and ureolytic cycle as their basic metabolic pathway. Characterisation studies were performed and the most efficient isolate was obtained.