棉籽糖乳球菌Y-12产细菌素培养条件优化

摘要

Objective:Lactococcus raffinolactis Y-12 was isolated from Dushan pickled Chinese cabbage,and the fermentation conditions of bacteriocin produced from it were optimized.Methods:The factors including fermentation time,temperature,initial pH,glucose and so on,that affected the yield of bacteriocin,were studied in single factor and Plackett-Burman optimization test.On the basis of single factor test and Plackett-Burman treatment,the conditions for bacteriocin production were explored by Box-Behnken design involving the peptone,glucose and initial pH at three levels in combination with response surface methodology.Results:The optimal combination of the medium constituents for bacteriocin production were as follows:fermentation temperature 35 ℃,fermentation time 36 h,inoculums concentration 2％,10.62 g/L peptone,31.61 g/L glucose,initial pH6.46,the other composition of MRS medium were unchange.Under the optimal condition,the inhibitory zone diameter was 16.87 mm,than before optimization (14.12 mm)to improve 19.5％.Conclusion:The experimental results were in agreement with the prediction values,indicated the established regression model was feasible.%目的:以分离自独山盐酸菜产细菌素棉籽糖乳球菌Y-12为研究对象,对其产细菌素培养条件进行优化.方法:利用单因素和Plaekett-Burman实验确定发酵温度、发酵时间、初始pH和葡萄糖浓度等发酵条件水平值,在单因素和Plackett-Burman实验的基础上,采用Box-Behnken法设计三因素三水平实验进行响应面优化,确定菌株Y-12产细菌素最佳发酵条件.结果:菌株Y-12产细菌素最佳发酵条件为:发酵温度35℃、发酵时间36 h、接种量2％、蛋白胨10.62 g/L、葡萄糖31.61 g/L,初始pH6.46,其他成分(同MRS培养基)保持不变.在此条件下,细菌素抑菌圈直径达16.87 mm,比优化前(14.12mm)提高19.5％.结论:在最优条件下获得实验结果与模型预测值吻合,说明所建立回归方程模型切实可行.