Optimization of the Medium for Production of Neutral Protease and Research of the Enzymatic Properties

Response surface analysis was applied to optimize the medium for production of neutral protease.The result showed that the optimum medium formula compositions were flour 2.24 g,peanut meal 8.46 g and calcium chloride 0.028 g,under which the neutral protease activity was up to 15559.40 U/g.The optimum pH and temperature for neutral protease were 7.0 and 50 ℃,respectively.The protease was stable at pH 5.0~7.0 and at 40~55 ℃.The tested metal ions did not significantly activate the protease,while the ions Ba2+,Fe2+,Zn2+ and Cu2+ strongly inhabited its activity.