Study on characteristics of protease produced by Mucor racemosus and its application in the production of soybean peptide

The characteristics of protease produced by Mucor racemosus were investig ated by the determination of enzyme activity. The results showed that the main secretion stage of protease by M. racemosus was during the 5th to 6th day in culture. The optimum pH of protease was ranged be-tween 4.0 and 6.0,and in such a case,the protease was more stable. The optimum temperature of protease ranged from 45℃ to 55℃. The highest ac-tivity of protease was achieved at 50℃. The protease was much more stable when it was kept under 40℃. It was also indicated that 1.0% NaCl,1.0% CaCl2,1.0% MnSO4 and 1.0% MgSO4 had positive effects on the activity of protease,but 1.0% KCl,1.0% ZnSO4 and 1.0%CuSO4 could suppress the the activity of protease at different degree. The soybean peptide produced with this protease has a better quality.