Lactobacillus fermentum F6的增殖培养基优化及高密度发酵的研究
摘要
To optimize the enrichment medium components and the high-density cultivation procedure of Lactobacillus fermentum F6, this was isolated from traditional dairy products of minority nationalities. Detected OD600 (optical density under 600 nm) in different medium and bacterial colonies were counted under different high-density cultivation conditions. The composition of enrichment medium for Lactobacillus fermentum F6 was as follows: sucrose 62.0 g/L, yeast extract 35.5 g/L, soy peptone 12.0 g/L., citric acid 1.35 g/L, citrate sodium 22 g/L, MgSO4•7H2O 2 g L, MnSO4•5H2O 100 mg/L. and Tween-80 1.0 g/L. After high-density cultivation in enrichment medium with optimized conditions, the living cells of fermentation broth and powder were 2.30×10^10 CFU/mL and 1.45×10^11 CFU/g, respectively. The survival rate after freeze-drying with cryoprotector was 79.11%. The count of living cells in fermentation broth of plot plant scale test could reach to 1.02×10^10 CFU/mL, the survival rate was 58%. The result can provide some useful data to the industrial application of Lactobacillus fermentum F6.