Biomineralization using Synechococcus Pevalleikii and its Applications in Building Material

Abstract

Concrete is a broadly utilized building material with a worldwide generation increasing by 2.5% every year and anticipated that would achieve USD 954.7 billion by 2024. However, concrete has a limited lifespan and can be deteriorated easily. Microbially induced carbonate precipitation (MICP) by nitrogen-involved heterotrophic bacteria showed great potential for crack healing and concrete recycling. This study investigated the role of autophototrophs as alternative technology to conquer the pollution created by urea-based MICP. The calcification by Synechococcus pevalleikii was studied in concrete solution and cubes, and studied the effect on concrete properties. The pH, calcium concentration and cell viability were examined and scanning electron microscopic studies indicated the morphologies of the minerals produced were majorly cubic and rhombic crystals. Based on laboratory experiments S. pevalleikii remained intact in the cement pore solution and a thick layer of calcite and cells were found attached to the concrete cubes. Morphologies and amount of crystals from biotic-formed precipitates differs greatly from abiotic-formed ones. Treatments with UV-killed cells improved the compressive strength and decreased the water absorption. Consequently, the technology of using autophototrophs is promising with great potential for restoring concrete.