The microbial consortia incorporated in bio concrete should have traits such as high alkali resistance and the ability to form endospores to overcome the mechanical and chemical stresses produced during concrete preparation. The primary intent of our work is to segregate and identify the calcium carbonate precipitating microorganisms with a strong urease activity, compare their potential for the preparation of bio concrete, and evaluate its performance, durability, and effects on heavy metal toxicity. Bacteria, algae, protozoans, yeasts, and fungi are predominantly reported in the consortia of microbes in a construction sample, making it an excellent source of wild microbial species and strains which have adapted to the environment of the construction place which consists of a consortium of limestone, fine sand, and curing water. Consortia of organisms were isolated from fermented lime mortar and curing construction water, which was recognized using the 16S rRNA gene sequencing technique. Atomic Absorption Spectrometry[AAS] and Inductively Coupled Plasma Mass Spectrometry[ICP-MS] were carried out to analyze the deduction of heavy metal toxicity present in the produced bio concrete. The results of strength and toxicity tests were compared with bio-concrete produced from standard cultures of Bacillus megaterium (NDRI-067) and Bacillus licheniformis(NDRI-598) obtained from the National Dairy Research Institute. (NDRI), and also compared with conventional concrete.