Abstract:
Concrete that used in construction is often subject to crack. One of the efforts to prevent concrete cracks is by using ureolytic bacteria. Ureolytic bacteria are bacteria that can produce urease enzymes, can precipitate CaCO3 and have potency as self-healing concrete. The purpose of this research was to optimize ureolytic bacteria SP 48 at variations of pH 8, 9, 10 and variations in the number of 106cfu/ml, 107cfu/ml, 108cfu/ml inoculum in precipitating CaCO3 using 7 days NB-U/Ca medium with a temperature of 30oC speed 130 rpm. The results obtained that pH 8 and 9 were not significantly different from the amount of CaCO3 produced by SP 48 with the number of precipitates of 137 mg and 123 mg respectively. The results of the variation of the number of inoculums showed that the number of inoculums 106cfu/ml, 107cfu/ml, 108cfu/ml did not significantly affect the amount of CaCO3 produced by SP 48 isolates.
