嗜酸乳杆菌NX2-6产细菌素的发酵条件优化

Optimization of Fermentation Conditions for Bacteriocin Production by Lactobacillus acidophilus NX2-6

在Plackett-Burman试验结果基础上,采用响应曲面法(Box-Behnken设计)对嗜酸乳杆菌NX2-6发酵产细菌素的关键影响因素,即葡萄糖质量浓度、乙酸钠质量浓度、柠檬酸三钠水合物质量浓度及培养时间的最佳水平范围进行研究和探讨。通过对发酵液抑菌圈直径的二次多项回归方程求解得知,在葡萄糖质量浓度、乙酸钠质量浓度、柠檬酸三钠水合物质量浓度和培养时间分别为60.0、8.0、5.0g/L和36h时,菌株NX2-6的发酵液抑菌圈直径预测值为21.37mm,验证实验抑菌圈直径实测值与预测值的相关系数R2为0.9918。优化后培养基与基础培养基相比,发酵液抗菌活性增加约80.0%,由此可见,利用响应曲面法对嗜酸乳杆菌NX2-6发酵产细菌素条件进行优化是经济有效且科学合理的。

Three culture medium components including glucose,sodium acetate and sodium citrate and fermentation time were identified as key factors that affect bacteriocin production by Lactobacillus acidophilus NX2-6 using a Plackett-Burman design and their optimal levels were investigated using response surface methodology based on a Box-Behnken experimental desiign.The optimal levels of glucose,sodium acetate and sodium citrate concentrations and fermentation time were determined to be 60.0 g/L,8.0 g/L,5.0 g/L and 36 h,respectively based on the established quadratic polynormial regression equation for inhibition zone diameter of fermentaton broth.Under these conditions,the predicted inhibition zone diameter of fermentaton broth was 0.9918.The optimized culture medium resulted in an increase of approximately 80.0% in the antibacterial activity of fermentation broth compared to the basic culture medium.Therefore,response surface methodology can provide an economic,effective and reasonal strategy for the optimization of fermentation conditions for bacteriocin production by Lactobacillus acidophilus NX2-6.