청국장으로부터 단백질 분해효소 생산을 위한 Bacillus 균주 분리 및 효소 생산조건 최적화

Abstract

This study was performed to investigate the optimum condition of protease production from submerged culture using Bacillus subtilis SM4 isolated from Korean bean paste. The medium adding bean sprouts powder to YP medium (YPS) resulted in 8.82 unit/mL protease activity which showed an increase 33.2% compared to YP medium. Among several carbon sources, fructose (2.25%, w/v) yielded 95.4 unit/mL of maximum protease activity. Comparison of different nitrogen sources indicated that 2.25% (w/v) casein showed the highest protease activity of 385.4 unit/mL. In the temperature optimization experiment, it was confirmed that the production of protease using B. subtilis SM4 occurred in the fermentation temperature of 25℃. The optimum temperature for the production of protease was 25℃ indicating B. subtilis SM4 protease would be suitable for the hydrolysis of protein and the production of functional peptide from agro-industrial byproducts at low temperature. The maximum enzyme production of 568.5 unit/mL was obtained from the optimization of medium compositions and incubation conditions, which showed that B. subtilis SM4 protease could be replaced commercial enzymes for the hydrolysis of proteins from agro-industrial byproducts.