Optimization of Fermentation Conditions for Exopolysaccharid Production from Lactobacillus lactis

This study aims to increase exopolysaccharid production d by optimizing the culture and nutrient conditions of Lactobacillus lactis.The results showed that Elliker was the optimum medium.Three statistically significant ingredients,yeast extract,the initial pH and fermentation time,which were determined by Plackett-Burman design.Based on the results of the first phase,the five-level three-factor central composite design was employed to optimize the above critical factors.The exopolysaccharid titer was achieved at 3.910 g/L,with the combination of yeast extract 17.35 g/L,the initial pH 5.85,fermentation time 23.18 h.