Comparative genomics and biomineralization potential of a native ureolytic Bacillus sp. N₉ for microbially induced...

Microbially induced calcite precipitation (MICP) has emerged as a sustainable biotechnological approach for soil stabilization and environmental remediation. However, the efficiency of MICP largely depends on selecting environmentally adapted ureolytic bacterial strains with robust biomineralization potential. In the present study, a native marine ureolytic isolate, Bacillus sp. N₉, was comparatively evaluated against selected MICP-associated bacteria using integrated comparative genomics and in vitro functional analyses. Genome-based taxonomic assessment revealed phylogenetic proximity of Bacillus sp. N₉ with Lederbergia lenta, while whole-genome phylogeny distinguished the isolate from conventional ureolytic Sporosarcina strains. Pan-genome analysis of selected ureolytic bacteria suggested extensive genomic diversity, with a predominance of accessory and cloud genes, indicating high genomic plasticity among MICP-associated taxa. Comparative analysis of urease structural genes (ureA, ureB, and ureC) showed strong conservation with closely related taxa, while moderate divergence from conventional Sporosarcina strains suggested evolutionary diversification of ureolytic pathways. Synteny analysis further confirmed conservation of urease gene clusters across related genomes. Functional assessment under standardized urea-CaCl₂ conditions indicated progressive alkalinization and visible CaCO₃ precipitation by both Bacillus sp. N₉ and Sporosarcina ureae MTCC 9133. The observed increase in medium pH under urea-supplemented conditions by Bacillus sp. N₉ is suggestive of active ureolysis, reflecting the net accumulation of ammonium (NH₄) and carbonate ions (CO₃²⁻), generated through urease-mediated urea hydrolysis. The study establishes a genome-to-function framework for evaluating native ureolytic bacteria and highlights the significance of environmentally adapted microbial strains for sustainable MICP applications.