Influencing factors and formation mechanism of CaCO3 precipitation induced by microbial carbonic anhydrase. (April 2020)

• Record Type: Journal Article
• Authors: Zheng, Tianwen; Qian, Chunxiang
• Is Part Of: Process biochemistry. Volume 91(2020)
• Page Start: 271
• Page End: 281
• Publication Date: 2020-04
• Subjects: Carbonic anhydrase -- Calcification rate -- CaCO3 precipitation -- Mechanism -- CO2 hydration; Biochemical engineering -- Periodicals; Biotechnology -- Periodicals; Biochemistry -- periodicals; Biotechnology -- periodicals; Chemical Engineering -- periodicals; Génie biochimique -- Périodiques; Biotechnologie -- Périodiques; Biochemical engineering; Biotechnology; Periodicals; 660.63
• DOI: 10.1016/j.procbio.2019.12.018
• Languages: English
• ISSNs: 1359-5113

Abstract

Graphical abstract: The mechanism of microbial induced calcium carbonate precipitation (MICP). Highlights: Discussed the factors affecting carbonic anhydrase growth and enzyme activity. Studied the changes of Ca 2+ concentration and calcification rate in the solution. Revealed the dynamic process of microbial induced calcium carbonate precipitation. Optimized the mechanism of carbonic anhydrase accelerating CO2 hydration. Established the model of microbial induced calcium carbonate precipitation. Abstract: Microbial carbonic anhydrase promotes carbonate deposition, which is important in the formation and evolution of global carbon cycle and geological processes. A kind of bacteria producing extracellular carbonic anhydrase was selected to study the effects of temperature, pH value and Ca 2+ concentration on bacterial growth, carbonic anhydrase activity and calcification rate in this paper. The results showed that the activity of carbonic anhydrase at 30 °C was the highest, which was beneficial to the calcification reaction, calcification rate of CaCO3 was the fastest in alkaline environment with the initial pH value of 9.0. When the Ca2+ concentration was 60 mM, compared with other Ca 2+ concentration, CA bacteria could grow and reproduce best, and the activity of bacteria was the highest, too low Ca 2+ concentration would affect the generation of CaCO3, while too high Ca 2+ concentration would seriously affect the growth of bacteria and reduce the calcification rate. Finally, the mechanism of CaCO3 precipitation induced by microbial carbonic anhydrase was studied. Carbonic anhydrase can accelerate the hydration of CO2 into HCO3 −, and react with OH − and Ca 2+ to form CaCO3 precipitation in alkaline environment and in the presence of calcium source.