# Potential of enzymes (urease and carbonic anhydrase) for a sustainable construction industry

MARIA J. CASTRO1, CARLOS E. LÓPEZ1, RAJESWARI NARAYANASAMY2, JOLANTA E. MARSZALEK1, MIRIAM P. LUEVANOS-ESCAREÑO1, GERARDO J. FAJARDO3, NAGAMANI BALAGURUSAMY1*
*Corresponding author
1. Laboratorio de Bioremediación, Facultad de Ciencias Biológicas, Universidad Autónoma de Coahuila, Carretera Torreón-Matamoros km 7.5 Torreón Coahuila, México
3. Facultad de Ingeniería Civil de la Universidad Autónoma de Nuevo León

## Abstract

Concrete is the most commonly used material of numerous structures around the world due to resistance, durability and low cost compared with other construction materials. However, traditional construction materials are susceptible to suffer deterioration by physical, chemical and biological factors that produce irreversible damage to their structure, which requires a high-cost of repair and maintenance. Additionally, during production process cement industry emits about 0.73 – 0.99 t CO2/ t of cement produced. Bioconcrete is emerging as an ecological, economical and sustainable alternative for construction industry. Biomineralization by bacteria facilitates the development of bioconcrete, wherein calcium carbonate is formed by the metabolic activity of microorganisms, which involves a series of complex reactions directed mainly by urease and carbonic anhydrase enzymes. In this review, biomineralization processes involved in bioconcrete formation and their potential use for the construction industry is discussed.

INTRODUCTION

Concrete is widely used as construction material around the world due to its resistance, durability and low cost in comparison with other construction materials (1,2). However, it is susceptible to undergo deteriorations due to diverse physico-chemical and biological factors (3,4). These factors induce formation of cracks in internal structure of concrete causing irreversible damage. It has been estimated that the cost of repair and maintenance is around $147/m3 of concrete, despite the fact that cost of concrete production ranges between$65 and \$80/m3 (5). Cement is the most important component of the concrete since it provides properties of compaction, and with growth of modernization and industrialization demand for cement has been increasing. The demand for cement in 2006 was about 2540 million tons (Mt), which is predicted to increase between 3680 (low estimate) and 4380 Mt (high estimate) in 2050. This increase in activity of the construction industry has generated a negative impact on the environment. Concrete industry emits 0.73 – 0.99 t CO2/ t of cement produced (6), which accounts for about 5-7% of global CO2 emission (2, 7). Re ...