Optimization fermentation medium of K.lactisK1-16-7 for lactulose production

Plackett-Burman design and response surface analysis were used to optimize the fermentation medium of K.lactisK1-16-7. Based on the results of Plackett-Burman design, important factors affecting the yield of β-galactosidase were yeast extract, peptone F403, lactose, MgSO4 and KH2PO4. Then, The five factors were further optimized using response surface analysis. The optimizated fermentation medium was yeast extract 10.7 g/L, peptone F403 9.4 g/L, lactose 12.1 g/L, MgSO4 5.6 g/L, KH2PO4 4.7 g/L. After the optimization, the yield of β-galactosidase was increased 88.7%, reached 147.6 U/g.