Biocementing potential of ureolytic Bacillus sp. and Streptomyces sp. in the cohesion of sand particles

Abstract Concrete can be engineered with self-healing capabilities using bacteria, providing an eco-friendly and sustainable alternative to traditional repairs. This research evaluated the biocementing potential of Bacillus sp. and Streptomyces sp. by analyzing their resistance to stress conditions (pH 8 and 10) and their ability to produce calcium carbonate. Both strains showed stable growth; however, Bacillus sp. generated a higher formation of crystals, identified as vaterite and syn-vaterite, confirmed by SEM and EDS. In sand columns, Bacillus sp. increased cohesion thanks to the formation of cementing bridges with high surface area, while Streptomyces sp. showed limited action. The results demonstrate that Bacillus sp. is the more promising candidate for the development of sustainable self-healing concrete.