![]() ![]() This process is facilitated through the ingress of water, CO 2 and other chemical substances such as SO 4 and NO 3 -, among others ( De Muynck et al., 2008 Jonkers et al., 2010 Dhami et al., 2014 Achal and Mukherjee, 2015 Bundur et al., 2015 Verma et al., 2015), aids in self-healing and improves the physical and mechanical properties of the concrete structure. Bioconcrete production is based on the addition of bacteria with the ability to induce the formation of minerals (biomineralization) from the cement matrix. In the last two decades, incorporation of a bacterial metabolic process known as Microbially Induced Calcium Carbonate Precipitation (MICP) has emerged as an alternative method to reduce the cost and environmental impact. Although the global cost of concrete production ranges between € 60/m 3 to € 75/m 3, the average cost for crack repair in Europe is about € 130/ m 3 ( Silva et al., 2015), which reveals the high cost involved in the maintenance and repair of concrete structures. These factors cause microcracks formation, which affect mechanical and durability properties of concrete such as compressive strength, flexural strength, and permeability, consequently reducing the useful life of concrete ( Achal and Mukherjee, 2015) and increasing the cost of the maintenance and repair of infrastructures. Increase in consumption of concrete is a consequence of the susceptibility of infrastructures to physical, chemical and biological factors such as temperature variations, exposure to corrosive and radioactive substances, aggressive gases, natural disasters, and microbial activity ( Jroundi et al., 2010 Narayanasamy et al., 2010 Achal et al., 2016 Siddique et al., 2016 Turick and Berry, 2016 Van Tittelboom et al., 2016). The industrial process involved in cement production from lime (precursor of concrete), consumes between 2 and 3% of the global energy demand, generating 0.73–0.99 t CO 2/t of cement produced, which accounts for about 8–10% of the global anthropogenic emissions of CO 2 and 3.4% of the total CO 2 global emissions ( Achal et al., 2016 Aprianti, 2017 Miller et al., 2018). Annually, more than 10 billion tons of concrete are used at a global level and experts have predicted that the concrete demand is likely to grow to 16 billion tons in 2050 The current technology employed by the construction industry generates a negative impact on the global environment and economy. It is clearly evident that microbiological and molecular components are essential to improving the process and performance of bioconcrete.Ĭoncrete is the most used construction material due to its resistance, durability and low cost in comparison to other construction materials. 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. MICP by urea hydrolysis is induced by a series of reactions driven by urease (Ur) and carbonic anhydrase (CA). Among the metabolic processes mentioned above, urea hydrolysis is the most applied in concrete repair mechanisms. 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. 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. Some of the major metabolic processes involved in MICP at different levels are urea hydrolysis, denitrification, dissimilatory sulfate reduction, and photosynthesis. MICP is an outcome of metabolic interactions between diverse microbial communities with organic and/or inorganic compounds present in the environment. MICP is a widespread biochemical process in soils, caves, freshwater, marine sediments, and hypersaline habitats. ![]() ![]() In this review, we discuss microbiological and molecular concepts of Microbially Induced Calcium Carbonate Precipitation (MICP) and their role in bioconcrete. 2Facultad de Ingeniería, Ciencias y Arquitectura, Unidad Gomez Palacio, Universidad Juárez del Estado de Durango, Durango, Mexico.1Laboratorio de Biorremediación, Facultad de Ciencias Biológicas, Universidad Autónoma de Coahuila, Torreón, Mexico.María José Castro-Alonso 1, Lilia Ernestina Montañez-Hernandez 1, Maria Alejandra Sanchez-Muñoz 1, Mariel Rubi Macias Franco 1, Rajeswari Narayanasamy 2 * and Nagamani Balagurusamy 1 * ![]()
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