Protease production from Bacillus safensis in submerged fermentation using response surface methodology

In present study, various cultural parameters for Bacillus safensis were optimized in submerged fermentation for alkaline protease production using response surface methodology. Nutritional components were screened through Placket-Burman design. The optimized cultural parameters were, 1% inoculum, initial medium pH 9.0, incubation temperature 30OC and fermentation time 72h. Among nutritional parameters, casein, KH2PO4 and peptone were found significant which were further optimized through Box-Bhenken Design with three levels. The experimental results showed that 4.0% casein, 0.05% KH2PO4 and 0.575% peptone yielded highest protease production. The proposed model was significant which clearly explained the response. The crude protease produced by Bacillus safensis showed optimum activity at pH 8.0 and at 40oC. Kinetics revealed that the Km and Vmax values of 1.027 mg/ml and 67.57 mg/ml/min using casein as substrate, respectively.

Keywords: Alkaline protease, Bacillus sp, RSM, characterization, submerged fermentation.