植物乳杆菌R23 MLE酶学特性研究

Study on the Properties of Malolactic Enzyme of Lactobacillus Plantarum R23

目的：为苹果酸-乳酸酶（MLE）酶制剂的生产和酶的固定化应用提供研究基础。方法：以植物乳杆菌R23为材料,研究其MLE的适宜反应温度、pH值以及影响因子对酶活力的影响,建立MLE的酶促反应动力学方程。结果及结论：植物乳杆菌R23 MLE的适宜酶促反应温度24-27℃,pH 6.0。L-乳酸和SO2对MLE酶促反应具有抑制作用,而NAD＋和Mn2＋对MLE的酶促反应有促进作用,NAD＋和Mn2＋适宜的添加量分别为1.0 mmol/L和100.0μmol/L。植物乳杆菌R23 MLE酶促反应的米氏方程：1/v=0.0087×1/[s]＋0.0023（R2=0.9936）,米氏常数Km=3.78×10^-3mol/L。

Objective：To provide theoretical basis for produing malolactic enzyme or immobilized enzyme.Methods：The optimum reaction temperature,pH value,and effects of the factors on activities of MLE of Lactobacillus plantarum R23 were studied,the enzymatic reaction kinetics equation of MLE was esteblished.Results and Conclusion：The opti-mum conditions of enzymatic reaction for Lactobacillus plantarum R23 were under pH 6.0 and temperature at 24~27 ℃.L-latic acid and SO2 showed against the enzymatic reaction of MLE.However,NAD＋and Mn2＋showed positive effects on the enzyme reaction,which proper added conentrations were 1.0 mmol/L and 100 μmol/L respectively.The Michaelis e-quation of enzymatic reaction of MLE was：1/v=0.0087×1/[s]＋0.0023（R2=0.9936）,and the Km was 3.78×10-3mmol/L.