Assessment of cyanobacterial species for carbonate precipitation on mortar surface under different conditions

Microbial carbonate precipitation (MCP) has the potential to restore concrete, contributing to a longer lifespan of construction. The MCP process starts with microbes attaching to the damaged substrate, and completes with carbonate precipitation. Tremendous studies have focused on ureolytic bacteria, while this research investigated the function of cyanobacteria by monitoring the chemical variation of solution, morphological and spectroscopic changes of mortar surfaces. By comparing the biomineralization mediated by three cyanobacterial species in experimental solutions and on mortar surfaces, this study concludes that Synechocystis PCC6803 exerted the highest impact in carbonate precipitation under both conditions. Environmental factors such as viability of cells, UV exposure and light intensity modified the MCP processes of Syn. PCC6803 and Synechococcus LS0519, but not Synechococcus PCC8806. UV-killed Syn. PCC6803 brought about the highest rate of carbonate precipitation.