Abstract: The high cell density culture of Lactobacillus buchneri IMAU80233 with potential probiotic characteristics was optimized for industrial production in this study. MRS medium was improved and rapid selection and optimization of suitable medium components for the growth and proliferation of this strain were carried out using Bioscreen C system. The optimal medium composition was determined as follows: fructose 80 g/L, soybean peptone 23.90 g/L, yeast powder 11.90 g/L, citric acid 1.59 g/L, sodium citrate 20.06 g/L, MnSO4·5H2O 0.09 g/L, MgSO4·7H2O 0.60 g/L, arginine 0.50 g/L, and Tween-80 1.00 g/L. Five-liter fermenters (× 3) were used to carry out small-scale experiments. The initial pH value was 6.5, and IMAU80233 was cultured at 37 ℃ for 20 h during which the pH was held constant at 5.9. Nitrogen gas was introduced during the initial fermentation stage. Under the optimized conditions, the viable cell count of the fermentation broth was 3.81 × 109 CFU/mL.

Key words: Lactobacillus buchneri, maximum specific growth rate, medium optimization, high cell density fermentation