戊糖乳杆菌高密度培养技术

High Cell-density Culture Technology of Lactobacillus Pentosus

以MRS培养基为基础,优化培养条件和培养基成分,采用补料分批培养法进行戊糖乳杆菌的高密度培养。最佳培养条件是:接种量3%,pH 6.5,培养时间20 h。最佳培养基成分:蛋白胨1.5%,葡萄糖2%,缓冲盐磷酸氢二钾1%,以0.15%VB5或0.5%谷酰胺酸为生长因子。优化的补料策略是:补料的碳氮源比2∶1.5,补料总量7.5%,即初始补料2.5%,4 h和8 h后各补料2.5%,得到的活菌数2.36×109CFU/mL,为常规培养的5倍。

For high cell-density cuhure of Lactobacillus pentosus, the culture conditions, medium composition and fed batch cultivation were optimized based on MRS medium. The optimum culture conditions were： inoculum size of 3%, pH 6.5, incubation time of 20 h. The optimum medium composition were： peptone of 1.5%, glucose of 2%, dipotassium hydrogen phosphate buffer salt of 1% and using glutamine acid and VB5 as growth factor. On this basis, feeding a cer- tain carbon nitrogen ratio （2：1.5） and the total amount of 7.5%, that was the initial feeding of 2.5%, feeding 2.5% after 4 h and 8 h respectively, which obtained the highest viable count of 2.36×10^9 CFU/mL, 5 times of the normal culture.