Abstract:The proliferation culture medium of Lactobacillus fermentum SS-31 which was isolated from the fermentation broth of sour bamboo shoots in Liuzhou, Guangxi, with excellent probiotic properties, was optimized and its high-density fermentation conditions were explored. The composition of fermentation and proliferation medium as well as the culture conditions were optimized using the viable bacteria number of Lactobacillus fermentum SS-31 as the main reference index through single factor experiment, response surface optimization and other experimental methods. The final composition of Lactobacillus fermentum SS-31 medium was optimized with maltose of 16.20 g/L, yeast extract of 20.16 g/L, dipotassium hydrogen phosphate of 9.33 g/L, manganese sulfate of 0.50 g/L, magnesium sulfate of 1.00 g/L, and Tween of 1.00 g/L. The optimal fermentation conditions were set as 3% of inoculum size of SS-31, pH 6.8 of initial pH value with ammonia added to maintain the pH of fermentation broth, under which the viable count of Lactobacillus fermentum SS-31 reached 1.19×1010 CFU/mL cultured at 37 ℃ for 24 h, laying a foundation for its industrial production.
