Optimization for the maximum bacteriocin production of Lactobacillus brevis DF01 using response surface methodology

To enhance the production of bacteriocin DF01, produced by Lactobacillus brevis DF01, cultivation conditions and medium composition were optimized by using response surface methodology (RSM). The selected 5 factors based on MRS medium were glucose, yeast extract, MgSO4, temperature, and initial pH. Fractional factorial design (FFD) was effective in searching for the main factors. By a 2(5-1) FFD, glucose, yeast extract, and initial pH were found to be significant factors and had positive effects on bacteriocin production. The effects of the 3 main factors on bacteriocin production were further investigated by a central composite design (CCD). RSM revealed that the maximum bacteriocin production was achieved at yeast extract concentration of 14.56 g/L, glucose concentration of 28.95 g/L, and initial pH of 6.8. After RSM, the titer of bacteriocin was increased by 4-fold.