中心组合设计优化嗜酸乳杆菌NCU402增菌培养基

摘要

An initial medium for Lactobacillus acidophilus NCU402 (LaNCU402) was determined by single factor experiment.The maximum impact factor was designed by Two-level Fractional Factorial Design and the optimal region was obtained by Steepest Ascent.Central Composite Design and response surface analysis were used to confirm the optimized medium for LaNCU402.Optimized formula was as follows:glucose 1.5 ％,peptone 1％,beef extract 1.458 4％,yeast extract 0.4％,ammonium citrate 0.2％,K2HPO4 · 7H2O 0.2％,MgSO4 · 7H2O 0.02％,MnSO4 · 4H2O 0.005％,NaAc · 3H2O 0.5％,lactose 1.766 5％,tomato juice 31.602 9％,Tween 80 0.1％.Viable cell concentration of LaNCU402 obtained by the optimized medium reached 2.883 3 × 109 CFU/mL,which was 5.029 times of the initial medium(MRS).The study herein provided theoretical basis for starter culture production.%为筛选优化适合嗜酸乳杆菌LaNCU402高密度培养的增菌培养基,通过单因素法筛选基础优化培养基、二水平部分因子设计(two-level fractional factorial design,FFD)获得最大影响因子、最速上升法(steepest ascent,SA)试验获得最优点区域以及中心组合设计进行响应面分析得到最适增菌培养基.优化培养基配方为:葡萄糖1.5％、蛋白胨1％、牛肉膏1.458 4％、酵母粉0.4％、柠檬酸三铵0.2％、K2 HPO4·7H2O 0.2％ 、MgSO4·7H,0 0.02％、MnSO4·4H20 0.005％、NaAc·3H2O 0.5％、乳糖1.766 5％、番茄汁31.602 9％、吐温800.1％;由此培养得到的活菌浓度可达到2.883 3×109 CFU/mL,是最初MRS的5.029倍.该结果可为以后的菌剂制备及工业化生产提供理论依据.