Ureolytic Lysinibacillus sp. Exhibiting Calcium Carbonate Precipitation with Effective Lead (Pb) Removal

Industrial effluents contaminated with heavy metals are a major environmental issue, prompting the need for sustainable bioremediation methods. Microbially induced calcium carbonate precipitation (MICP) is a remediation method that offers a long-term solution for enhancing soil mechanical properties, as well as reducing pollution from heavy metals. The objectives of the current study include screening and identifying native ureolytic bacteria from soil in Karad, as well as assessing calcite precipitation by ureolytic metallotolerant bacteria. The effectiveness of the isolated bacteria in removing lead as a heavy metal was tested in the medium. This research focuses on the removal of Pb heavy metal by using the MICP method. Samples of wastewater were taken from calcareous soils and effluents contaminated with heavy metals. Ureolytic bacteria were identified using urea agar medium, and nine positive isolates were obtained by using Christensen’s media. Ureolytic isolates were then screened for their tolerance to metal Pb²⁺ as well as calcium precipitation. The maximum tolerance ranged from 2 mM to 8 mM, depending on the metal ion. The potential isolate was identified through 16S rRNA gene sequencing. Lysinibacillus fusiformis was recognized as a urease-producing, metallotolerant bacterium with calcium precipitating. By using Lysinibacillus fusiformis, 85 % of the lead was removed. This is to evaluate Lysinibacillus-mediated MICP for Pb bioremediation from under environmentally relevant conditions, treated for real wastewater applications.”