【摘要】 用响应面(RSM)方法和正交试验对Lactobacillusdelbeueckiisubsp.bulgaricusS-1的培养基和分批培养条件进行了优化,为补料分批高密度培养提供基础。首先用一次回归正交试验对培养基组分葡萄糖、蛋白胨、牛肉膏、酵母膏、K2HPO4、柠檬酸铵、乙酸钠对细胞生长的影响进行评价,并找出主要影响因子为牛肉膏、柠檬酸铵、酵母膏,皆为正效应,其他组分影响不显著;第二步用最陡爬坡路径逼近最大响应区域;然后用中心组合设计确定主要影响因子的最佳浓度,最后对细胞分批培养的条件进行了优化。应用优化的培养基,在温度41℃,起始pH值6.8,接种量7%,培养时间12h的培养条件下,OD值为2.136,最高活菌数为2.1×109cfu/mL。更多还原

【Abstract】 Response surface methodology and orthogonal design were used to optimize the MRS-based culture medium and the batch culture condition of Lactobacillus delbeueckii subsp.bulgaricus S-1 respectively, which provided a basic work for the fed-batch culture, a culture method achieving high cell density. In the first optimization step, the effect of glucose, peptone, beef extract, yeast extract, K2HPO4, ammonium citrate and sodium acetate on cell growth was evaluated using linear regression orthogonal experiment. Beef extract, yeast extract and ammonium citrate were found had positive prominent effect but others had no prominent effect. The path of steepest ascent was used to approach the optimal region of the medium composition. The optimal concentrations of beef past, yeast extract and citrate amine were determined by a central composite design. At last, the condition of batch culture was optimized. The optimum culture condition of Lactobacillus delbeueckii subsp.bulgaricus S-1 under the optimized medium was as follows: culture temperature is 39℃ , optimum initial pH is 6.8, inoculums is 7% and culture time is 12h. Under this condition, OD value was 2.136 and the number of viable cells got to 2.1×109cfu/mL.更多还原