嗜酸乳杆菌Z-43高密度发酵配方及关键工艺条件优化

Optimization on formulation of high cell density fermentation and key processing for Lactobacillus acidophilus Z-43

目的筛选嗜酸乳杆菌Z-43最优增菌培养基,优化其关键发酵工艺条件,提升其高密度发酵水平。方法以碳源、氮源、生长因子为影响因素,分别设计单因素试验、碳源复配试验和氮源正交试验确定嗜酸乳杆菌Z-43最佳增殖培养基配方。结果最佳配方为葡萄糖1.25%(m:m)、蔗糖1.25%、酪蛋白胨1%、牛肉粉1.5%、鱼蛋白胨1%、大豆蛋白胨0.5%、胡萝卜汁10%、碳酸钙0.3%、吐温80 0.1%、脯氨酸0.02%、磷酸氢二钾0.2%、柠檬酸三铵0.2%、无水乙酸钠0.5%、一水合硫酸锰0.025%、七水合硫酸镁0.058%;通过梯度试验确定关键发酵工艺条件,最优接种量4%,初始pH6.5,培养温度39℃,将优化后发酵配方及工艺于10 L发酵罐进行生产发酵验证,发酵活菌数为3.12×10^(9) CFU/mL,是基础培养基的3.7倍。结论优化后的配方和工艺条件可大幅提升发酵水平,降低生产成本,提高产品经济效益。

Objective To select the optimal enrichment medium of Lactobacillus acidophilus Z-43, optimize its key fermentation conditions and improve its high-density fermentation level. Methods Taking carbon source, nitrogen source and growth factor as influencing factors, single factor test, carbon source compound test and nitrogen source orthogonal test were designed to determine the optimal formula of Lactobacillus acidophilus Z-43 proliferation medium. Results The best formula was glucose 1.25%(m:m), sucrose 1.25%, casein peptone 1%, beef powder 1.5%, fish peptone 1%, soybean peptone 0.5%, tomato juice 10%, calcium carbonate 0.3%, Tween 80 0.1%, proline 0.02%, dipotassium hydrogen phosphate 0.2%, triammonium citrate 0.2%, anhydrous sodium acetate 0.5%, manganese sulfate monohydrate 0.025%, magnesium sulfate heptahydrate 0.058%;The key fermentation conditions were determined by gradient test. The optimal inoculation amount was 4%, the initial pH was 6.5, and the culture temperature was 39 ℃. The optimized fermentation formula and process were verified in a 10 L fermentation tank. The number of live bacteria was 3.12×10^(9) CFU/mL, which was the 3.7 times of the basic medium. Conclusion The optimized formula and process conditions can greatly improve the fermentation level, reduce the production cost and improve the economic benefit of the product.