Cracks in concrete are the main cause to structural failure. The remediation of such building cracks can be done by incorporating an autonomous self – healing mechanism in concrete. A novel technique using live microbial cells bearing the capacity to precipitate calcite mineral is applied for healing the repair in concrete. In the present study two different microorganisms such as Bacillus sp and Pseudomonas aeruginosa were isolated and their ability to heal the micro cracks were compared. The results showed that the compressive strengths of the cubes containing live Bacillus sp increased than with Pseudomonas aeruginosa comparatively. It was observed that the cracks filled with bacteria and sand demonstrated a significant increase in compressive strength when compared with those without live cells. Bacillus sp showed increase in resistance towards water penetration than Pseudomonas aeruginosa and thus demonstrating that Bacillus sp being a spore former can enhance the durability of building materials.