Microbially Induced Calcium Carbonate Precipitation (MICP) and Its Potential in Bioconcrete: Microbiological and Molecular Concepts

Abstract

In this review, we discuss microbiological and molecular concepts of Microbially Induced Calcium Carbonate Precipitation (MICP) and their role in bioconcrete. MICP is a widespread biochemical process in soils, caves, freshwater, marine sediments, and hypersaline habitats. MICP is an outcome of metabolic interactions between diverse microbial communities with organic and/or inorganic compounds present in the environment. Some of the major metabolic processes involved in MICP at different levels are urea hydrolysis, denitrification, dissimilatory sulfate reduction, and photosynthesis. Currently, MICP directed by urea hydrolysis, denitrification, and dissimilatory sulfate reduction has been reported to aid in the development of bioconcrete and has demonstrated an improvement in the mechanical and durability properties of concrete. Bioconcrete is a promising sustainable technology which reduces negative environmental impact caused by CO 2 emissions from the construction sector, as well as in terms of economic benefits by way of promoting a self-healing process of concrete structures. Among the metabolic processes mentioned above, urea hydrolysis is the most applied in concrete repair mechanisms. MICP by urea hydrolysis is induced by a series of reactions driven by urease (Ur) and carbonic anhydrase (CA). Catalytic activity of these two enzymes depends on diverse parameters, which are currently being studied under laboratory conditions to better understand the biochemical mechanisms involved and their regulation in microorganisms. It is clearly evident that microbiological and molecular components are essential to improving the process and performance of bioconcrete.

Microbe‐Mediated Extracellular and Intracellular Mineralization: Environmental, Industrial, and Biotechnological Applications

“…Urea hydrolysis increases the pH around the cell and induces precipitation of CaCO 3 in the presence of soluble Ca 2+ (Figure 10B). [ 273 ] Soil shows remarkable improvements in strength, rigidity, permeability, and liquefaction resistance after MICP treatment. However, issues such as the homogeneity and durability of MICP‐treated soils still require further investigations.…”

Review of the use of microorganisms in geotechnical engineering applications

“…Hence, research into innovative and alternative approaches to ground improvement has focused on the use of biological processes. These techniques combine the usage of microorganisms, cementation reagents, and biological methods, which naturally exist in soils, to improve their engineering properties [3]. This approach results in minimal release of carbon dioxide into the environment, making it ecofriendly.…”

Research on Improving Concrete Durability by Biomineralization Technology

“…With the increase in environmental protection awareness, these environmentally unfriendly repair materials must be eliminated. In addition, the repair effect of these substances is not very significant due to compatibility issues with the concrete substrate, so researchers from various countries have been working toward environmentally friendly and sustainable repair of biological systems [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22].…”

“…Many studies have pointed out that small cracks in concrete can be repaired by themselves based on the continuous hydration of cement or other physical and mechanical behaviors [5,6,10,11,13,14]. In the field of concrete science, this phenomenon is often called "autogenous healing" or "concrete self-healing."…”

“…Therefore, biomineralization can often form an ordered natural organic-inorganic composite material with excellent structure. In view of this, in recent years, microbiologically induced calcium carbonate precipitation (MICP) technology based on microbial mineralization has become a hot topic in concrete self-healing technology and has attracted widespread attention in the academic community [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23].…”