Isolation, identification and growth conditions of calcite producing bacteria from urea-rich soil

Bacterial chemical reactions, such as urea hydrolysis can induce calcium carbonate precipitation. The induced production of formed by microorganisms has been widely used in environmental and engineering applications. present study aimed to isolate, identify optimize growth conditions urease positive bacteria from rich soil Gaza Strip. isolates, which tolerated ≥10% concentration, were selected for the investigation. Eight isolates recovered identified be spore forming, positive, alkaliphile, halotolerant, presumptively belonged Bacillus species.  All showed best at temperature 37°C, pH 9-9.5. After exposure UV irradiation, most improved tolerance however, other strains a decline their adaption concentrations. mutant form isolate sample #3 highest concentrations all intervals, when compared with wild type. Moreover, precipitated carbonate. locally are promising contributors process calcite Biomineralizaion may utilized remediation concrete cracks, increase compressive strength concrete, decrease water permeability, solve problems erosions.   Key words: Calcite bio-mineralization, microbial precipitation (MICP), urease, spp., strip.