Biocementation through the carbonic anhydrase (CA) activity of microorganisms -A review

Biocementation is the process of producing cement naturally through the metabolic activity of microorganisms. This technique has emerged as a sustainable alternative to conventional cement for various applications in the civil engineering construction industry, such as crack repairs in concrete or heritage buildings or soil stabilization, among others. While a few metabolic pathways have the potential to induce biocementation by mineral precipitation, most of the research works and applications of biocementation are based on urease enzyme mediated biocementation. Despite being the most straightforward process, the ureolysis route suffers from the disadvantage of ammonia production. The carbonic anhydrase pathway for biocementation is thus of interest due to its potential of producing biocement while also sequestering atmospheric CO2. This paper discusses the possibility of microorganisms sequestering CO2 and fixing it into different carbonate minerals using carbonic anhydrase activity. This contribution reviews this metabolic pathway and the few works that have studied it for applications such as CO2 sequestration and biocementation for civil engineering and environmental applications.