中性蛋白酶制备酪蛋白抗菌肽的研究

为了替代抗生素的广泛使用，防止病原菌耐药性大大提高，开发酪蛋白抗菌肽新型抗菌剂。本研究利用中性蛋白酶水解酪蛋白，以中性蛋白酶浓度、酶解时间、酶解温度、pH值为影响因子，在单因素试验结果的基础上，应用Centure-composite Design中心组合方法进行四因素三水平的实验设计，以酪蛋白水解液抑菌圈直径为响应值，运用响应面法对水解条件进行进一步的优化。结果表明：酶解温度、酶浓度、酶解时间、pH对酪蛋白水解液抑菌圈直径影响显著；酪蛋白抗菌肽制备的最佳工艺为：水解温度为50℃，酶浓度为3.73%，pH 7.9，酶解时间为130 min。回归方程预测酪蛋白水解液抑菌圈直径理论值可达到21.93 mm，3次验证实验的平均抑菌圈直径为21.91 mm，与理论最大值接近，可见该模型能较好地预测酪蛋白抗菌肽制备的最佳条件。

Research on Neutral Protease Preparation of Casein Antibacterial Peptide

In order to substitute the widespread use of antibiotics to prevent from pathogen resistance, we greatly enhanced the development of casein antimicrobial peptides. We hydrolyzed casein using neutral protease and based on neutral protease concentration, hydrolysis time, hydrolysis temperature and pH viewed as influence factors. We used single factor experiments and centure-composite design center combination method of four factors and three levels experimental design to further optimize hydrolysis condition. The results showed that, the effect of enzyme concentration, hydrolysis time, hydrolysis temperature and pH were significant. The conditions of casein antibacterial peptide preparation were optimized as following： enzyme concentration 3.73%, hydrolysis temperature 50℃, pH 7.9 and time 130 min. Regression equations predicting casein hydrolysate antibacterial ring diameter could reached 21.93 mm, the average degree of antibacterial ring diameter of three experiments could reached 21.91 mm, which was close to the theoretical maximum, showing that the model could predicted the optimal conditions of casein antibacterial peptide preparation.