Determination of peptidase production potential of Bacillus strains isolated from ropey bread and optimisation of some culture conditions for peptidase production

In this study, peptidase production potential of 14 Bacillus species isolated from ropey breads in a previous study, was determined at 30, 37, 50 and 55 °C. Then, optimum enzyme production medium composition and conditions for two of the strains which were found to have the highest peptidase activity were optimised with one factor at a time approach. For this purpose, carbon source, nitrogen source, carbon/nitrogen ratio, agitation rate and pre-culture medium which ensure the best peptidase activity were determined by considering the cost-effectiveness. The best carbon and nitrogen source was determined as glucose and yeast extract, respectively. Furthermore, higher peptidase activity was obtained with a carbon/nitrogen ratio of 1:5, agitation rate of 250 rpm and with the utilization of enzyme production medium for preparing pre-culture.