Effects of temperature and salinity on concrete-surface treatment by bacteria in marine environment

The present study investigated the effects of temperature and salinity on CaCO₃ production metabolism by soil bacteria. S. pasteurii was incubated in a urea-calcium lactate medium with the variables of salinity (0.5, 2, and 3.5%) at 10, 20, and 30°C. The effects of temperature and salinity on the growth, activity of urea hydrolysis, and CaCO₃ production were determined by comparing the growth rate and the changes in concentration of the NH₄⁺ and Ca²⁺. The effects of temperature and salinity on concrete surface treatment by S. pasteurii were conducted by water absorption test. The CaCO₃ precipitation metabolism of S. pasteurii was predominantly affected by temperature, while there was no significant difference in the metabolic capacity in terms of salinity. The water absorption rate of surface-treated concrete reduced with increasing temperature and salinity.