摘要
[ Objective] The aim of the research was to select alkaline pmtease-producing strains and provide basis for the application in production. [ Method ] An alkaline protease-preducing strain was isolated from the sea water and sea mud collected from Qingdao coastal area. After ultraviolet mutagenesis and microwave mutagenesis, a target strain ZR-58-3-1-3 was obtained. The protease activity and enzymatic properties of the strain were determined preliminarily. [ Result ] Prote- ase activity of the selected strain reached 145 U/ml. After the compound mutagenesis, protease activity of the fermentation liquid of strain ZR-58-3-1-3 reached 775 U/m｜, which was about 4.3 times higher than that of the original strain. The optimal temperature for alkaline protease produced by strain ZR-58-3-1-3 was 45℃, and the optimal pH was 8.5, suggesting it belongs to moderate temperature protease with relatively high thermal stabihty. [ Conclusion] Strain ZR-58-3-1-3 has stable alkaline protease production performance and can be used as an alkaline protease-producing mutant strain.
[ Objective] The aim of the research was to select alkaline pmtease-producing strains and provide basis for the application in production. [ Method ] An alkaline protease-preducing strain was isolated from the sea water and sea mud collected from Qingdao coastal area. After ultraviolet mutagenesis and microwave mutagenesis, a target strain ZR-58-3-1-3 was obtained. The protease activity and enzymatic properties of the strain were determined preliminarily. [ Result ] Prote- ase activity of the selected strain reached 145 U/ml. After the compound mutagenesis, protease activity of the fermentation liquid of strain ZR-58-3-1-3 reached 775 U/m｜, which was about 4.3 times higher than that of the original strain. The optimal temperature for alkaline protease produced by strain ZR-58-3-1-3 was 45℃, and the optimal pH was 8.5, suggesting it belongs to moderate temperature protease with relatively high thermal stabihty. [ Conclusion] Strain ZR-58-3-1-3 has stable alkaline protease production performance and can be used as an alkaline protease-producing mutant strain.
