Optimization of fermentation conditions of spores production of Bacillus licheniformis BL-5

Bacillus licheniformis,as one member of probiotics,has broad application prospects in the food and feed industries.According to the number and rate of Bacillus licheniformis BL-5 spores,the optimal conditions of fermentation was acquired via the Plackett- Burman experimental design,steepest ascent experimental design,and response surface experiment.And the results showed the optimized conditions were K~+concentration of 0.002 mol / L,Mg~(2+) concentration of 1 g/L,inoculation amount of 5%,inoculating age of 12 h,fermentation temperature of 30 ℃,fermentation time of 36 h.The optimum condition was verified,the rate and number of Bacillus licheniformis BL-5 spores were 94.67% and 3.32 × 10~9 CFU / mL,respectively.