粪肠球菌和酿酒酵母混合益生菌发酵条件的优化

Optimization of Fermentation Conditions for Enterococcus faecalis and Saccharomyces cerevisiae Mixed Probiotic Formulation

目的研究粪肠球菌与酿酒酵母混合培养发酵条件的优化。方法对粪肠球菌与酿酒酵母混合培养发酵条件进行优化,分析培养液初始p H、接种量及通气量对混合菌生长的影响。结果混合菌培养液最佳初始p H 7.0,在600 m L中试发酵罐(装液量40%)发酵温度30℃、通气量0.2 L/min、粪肠球菌和酿酒酵母接种量分别为2.0%和5.0%,发酵20 h,发酵结束时粪肠球菌和酿酒酵母总菌数约为3.8×108CFU/m L和2.4×108CFU/m L。通气量对于粪链球菌菌量差异无统计学意义(P>0.05),而对于酿酒酵母菌量差异具有统计学意义(P<0.05),结论优化发酵条件可获得较高水平的混合益生菌菌量,优化后粪肠球菌和酿酒酵母菌量分别提高了32.2%和31.5%,可为混合益生菌制剂大规模生产提供参考。

Objective To optimize the fermentation conditions for Enterococeus faecalis （ E.faeea/is ） and Saeeharomyees cerevisiae （ S.eerevisiae ） mixed culture. Methods The optimum fermentation conditions for E. faecalis and S. cerevisiae mixed culture were identified by investi- gating the influence of initial pH, inoculum size, and ventilation rate of the culture broth on mixed microbial growth. Results The optimal initial pH of mixed microbial culture was 7.0 and the inoculation amounts of E. Faeca/is and S. cerevisiae were 4% and 10% respectively, when fermented in 600-mL pilot fermentor （liquid volume 40%） at 30 ℃, with ventilation rate of 0.2 L/min, for 20 h. At the end of the fermentation, the E. faeca/is and S. cerevisiae counts were approximately 3.8 × 10^8 CFU/mL and 2.4× 10^8 CFU/mL, respectively. Ventilation for the amount difference of E. faecalis was no significant （P 〉 0.05 ）, and for the amount difference of S. eerevisiae was statistically significant （P 〈 0.05 ）. Conclusion The E. faeca/is and S. eerevisiae counts increased by 32.2% and 31.5% respectively, when the optimized conditions of fermentation culture were used. In this study, high mixed microbial counts were obtained, thus providing a reference for the preparation of large-scale production of mixed microbes.