Optimization of bacteriocin production by Lactobacillus plantarum YJG, isolated from the mucosa of the gut of healthy chickens

The objective was to develop an optimal, albeit low-cost medium for bacteriocin production, thereby facilitating industrial production. Soybean meal and peptide, two low-cost nitrogen sources often applied in industrial fermentation, were used to replace their expensive counterparts in De Man Rogosa and Sharpe (MRS). Two factors were first chosen from the 11 considered in the Plankett-Burman (PB) design. Then, the path of steepest ascent and central composite design (CCD) were used to approach the optimum region of the response and determine the maximum activity of the bacteriocin. Optimal concentration of glucose (36.3 g/l) and NaCl (1.41 g/l) stimulated the production of bacteriocins. And the optimal equation was then verified by 50 L fermentor. Under optimized conditions, Lactobacillus plantarum YJG produced a 1.4 fold higher production of bacteriocin than the common MRS, with 40.6% cost savings relative to non-optimized conditions.