Biomineralization and High Calcite Formation by Bacillus: Implications for Fiber Bio-Concrete Applications

Abstract

Concrete is essential in construction, yet its susceptibility to cracking is a major concern. This study explores biomineralization through Microbially Induced Calcite Precipitation (MICP) as an eco-friendly self-repairing solution that uses microbes to generate calcite for filling cracks. The research aimed to identify high calcite-producing Bacillus strains and optimize conditions for calcite formation to minimize cracking and maintenance requirements. Soil samples from Pakistan were used to isolate Bacillus strains via the ureolytic pathway. The process involved bacterial isolation, calcite production screening, and confirming ureolytic activity. Six urease-producing strains were identified, with Bacillus mojavensis and Bacillus pasteurii demonstrating the highest precipitation rates 27.39% at pH 7.5 and 35.90% at pH 8, respectively. Bacillus pasteurii showed notable resilience in harsh conditions, while Bacillus mojavensis improved concrete strength by 20% and Bacillus pasteurii by over 50%. Ureolytic bacteria enhances the autonomous healing, durability, and sustainability of concrete by effective calcium carbonate formation.