Microbially Induced Calcium Carbonate Precipitation by Sporosarcina pasteurii: a Case Study in Optimizing Biological...

Current production of traditional concrete requires enormous energy investment that accounts for approximately 5 to 8% of the world's annual CO₂ production. Biocement is a building material that is already in industrial use and has the potential to rival traditional concrete as a more convenient and more environmentally friendly alternative. Biocement relies on biological structures (enzymes, cells, and/or cellular superstructures) to mineralize and bind particles in aggregate materials (e.g., sand and soil particles). Sporosarcina pasteurii is a workhorse organism for biocementation, but most research to date has focused on S. pasteurii as a building material rather than a biological system. In this review, we synthesize available materials science, microbiology, biochemistry, and cell biology evidence regarding biological CaCO₃ precipitation and the role of microbes in microbially induced calcium carbonate precipitation (MICP) with a focus on S. pasteurii. Based on the available information, we provide a model that describes the molecular and cellular processes involved in converting feedstock material (urea and Ca²⁺) into cement. The model provides a foundational framework that we use to highlight particular targets for researchers as they proceed into optimizing the biology of MICP for biocement production.