碱性蛋白酶酶解罗非鱼下脚料蛋白动力学研究

Kinetic Model for Enzymatic Hydrolysis of Protein from Tilapia Waste

以加工罗非鱼片废弃的下脚料蛋白和碱性蛋白酶为原料,以水解度为指标,考察温度、底物质量浓度、酶用量及pH等因素对碱性蛋白酶酶解罗非鱼下脚料蛋白水解度的影响。得到碱性蛋白酶水解罗非鱼下脚料蛋白的适宜工艺条件为:酶解温度50℃、底物质量浓度20g/L、酶用量为0.067g/L、pH9.50、反应时间180min,此时水解度为22.00%。同时得到50℃条件下酶失活常数Kd为37.9min-1,反应速率常数K2为244.2min-1、米氏常数KM为29.27g/L、最大反应速度Vmax为28.41g/(min.L);并建立了相应的水解动力学模型。验证实验表明:建立的水解动力学模型与实际水解过程基本吻合。

Tilapia waste was used as the material to conduct hydrolysis by alkaline protease.The degree of hydrolysis（DH） of protein from tilapia waste was determined to explore the optimal enzymatic hydrolysis conditions.The results indicated that the optimal hydrolysis conditions for tilapia waste were hydrolysis temperature of 50 ℃,substrate concentration of 20 g/L,enzyme concentration of 0.067 g/L,hydrolysis pH of 9.50 and hydrolysis time of 180 min.Under the optimal hydrolysis conditions,the DH of tilapia waste was 22%.Meanwhile,a kinetic model of hydrolysis was established,which revealed an inactivation constant（Kd） of 37.9 min-1for enzyme,enzymatic reaction rate constant（K2） of 244.2 min-1,Michaelis-Menten constant（KM） of 29.27 g/L,and the maximum reaction rate（Vmax） of 28.41 g/（min.L） at 50 ℃.The kinetic equation of enzymatic hydrolysis of tilapia waste protein was derived.The proposed kinetic model exhibited a convenient determination of kinetic parameters by a few experiments.