Isolation and Characterisation of Urease Producing Bacteria and their Capacity to Precipitate Calcium Carbonate

The current study was designed to isolate and characterize urease-producing bacteria and to assess their ability to precipitate calcium carbonate. Total eight bacteria were isolated from dung-rich soil samples collected from Dakor, Gujarat. Out of these, two bacterial strains designated as DGDK-3 and DGDK-4 were found to produce a considerable level of urease in the initial screening on the urea agar medium. Based on morphological and physiological tests and more specifically by 16S rRNA gene sequencing analysis, these bacteria were identified as Quasibacillus sp. Strain DGDK-3 and Bacillus sp. Strain DGDK-4. The strains DGDK-3 and DGDK-4 showed 25 IU/ml and 89 IU/ml urease activity, respectively. Also, the efficacy of both strains was tested for calcium carbonate precipitation. Results showed that both the isolates were competent to precipitate a significant level of calcium carbonate. The current work demonstrated that urease-producing bacteria can be utilised in bio-cementationas a crack sealing agent and as a natural stabilizing agent.