Abstract: In this study, response surface methodology was applied to optimize medium composition for Lactobacillus plantarum, and high-density cultivation of L. plantarum was optimized by neutralization and exponential feeding method. On the basis of single-factor experiments, the optimal fermentation medium formula was determined by central composite design combined with response surface methodology to be made up of 5.43% glucose, 0.98% peptone and 0.59% K2HPO4. Ammonia neutralization and exponential feeding carbon and nitrogen sources together operated in a 15 L fermenter under the optimal conditions (inoculation amount of 3%, pH 6.5 and cultivation temperature of 35 ℃) resulted in a final cell concentration of up to 9.3×109 CFU/mL.

Key words: L. plantarum；response surface, medium optimization, high-density culture, exponential feeding batch