Isolation and Characterization of Calcifying Bacteria from Steel Slag and Their Role in Biomineralization

Abstract

Due to increased human activities and natural weathering processes like earthquakes, deterioration of construction materials has been occurring at increased rate. To sustain materials used in construction and to increase the service life of these materials, an optimum biotechnological method MICP has been exploited which causes production of microbial mortar. This method can be presented in a promising way to enhance the strength properties of cementitious materials. The objective of present work was to exploit the use of bacterial strain Bacillus megaterium or Staphylococcus pasteurii, which are isolated from alkaline environment of byproduct steel slag, in studying the enhancement of strength of mortar materials. Microbial process effectively reduced the water absorption levels i.e., less penetration of water occurred inside mortar specimens while increased compressive strength was also observed for the specimens with lower replacement levels. The present work mainly demonstrates the production of microbial mortar by ureolytic alkaliphilic bacteria and its utilization in strength enhancement of cement slag bacterial treated specimens. Partial replacement of cement with slag at lower levels can be taken into account on the basis of observed water absorption and strength properties and more studies can be further carried out for the same.