Freeze-dried co-cultured bacteria for enhanced calcium carbonate precipitation

Abstract

FREEZE-DRIED CO-CULTURED BACTERIA FOR ENHANCED CALCIUM CARBONATE PRECIPITATION ABSTRACT The present invention discloses a self-healing agent (10) for concrete cracks, comprising freeze-dried co-cultured bacteria (11) and cryoprotectants (12). The bacteria, Sporosarcina pasteurii, DSM 33 (101) and Bacillus subtilis, ATCC 6633 (102), are selected for their high urease activity, enabling efficient calcium carbonate precipitation. The cryoprotectants (12) are selected from the group consisting of: Deionized Water (103), Glycerol (104), Skim Milk (105), Sodium Glutamate (106) and Dimethyl Sulfoxide (107). Besides, the present invention also discloses a method (20) for the manufacture of a self-healing agent (10) to promote self-healing in concrete cracks. The method involves co-cultured bacterial (11) cultivation, centrifugation, addition of cryoprotectants (12), and freeze-drying. This process ensures long-term bacterial viability and effective reactivation upon exposure to moisture and nutrients in concrete. The present invention enhances concrete durability by promoting self-healing, reducing maintenance costs, and extending the lifespan of concrete structures. It offers significant advancements over traditional repair methods, contributing to sustainability and improved structural integrity. Most illustrated figure: Figure 1