Induced calcium carbonate precipitation using Bacillus species

Area of Science:

• Biotechnology
• Materials Science
• Geology

Background:

• Microbially induced calcium carbonate precipitation (MICP) is a promising technique for sustainable construction materials.
• Self-healing concrete utilizes MICP to autonomously repair cracks, enhancing durability and lifespan.
• Optimizing MICP is crucial for efficient and large-scale production of bio-concrete.

Purpose of the Study:

• To investigate the factors influencing calcium carbonate biosynthesis via MICP.
• To determine the optimal conditions for maximizing calcium carbonate production.
• To understand the microbial and environmental factors affecting the morphology of precipitated calcium carbonate.

Main Methods:

• Screening of bacterial genera (Bacillus licheniformis, Bacillus sphaericus) and their metabolic byproducts.
• Optimization of media components including yeast extract, urea, and calcium chloride.
• Controlled aeration and analysis of electron acceptors (Ca2+) for biomineralization.

Main Results:

• Identified Bacillus genera, yeast extract, urea, calcium chloride, and aeration as critical factors for MICP.
• Demonstrated that bacterial genera, media viscosity, and electron acceptors influence calcium carbonate morphology.
• Achieved a maximum calcium carbonate concentration of 33.78 g/L, the highest reported in scientific literature.

Conclusions:

• The study successfully identified optimal conditions for maximizing calcium carbonate production through MICP.
• The findings provide a foundation for the industrial application of MICP in self-healing concrete production.
• The achieved concentration represents a significant advancement in bio-mineralization for construction applications.