Abstract:

The intention of the current work was to obtain the optimal food-based medium and culture conditions for bacteriocin
production by Lactobacillus plantarum 163. The appropriate medium (1 L) containing 200 mL of cabbage juice, 50 mL of tomato
juice, 10 g of glucose, and 2 g of K2HPO4 in distilled water was selected for further optimization. Inoculum concentration, K2HPO4,
pH and cabbage juice were determined to be the key factors the influence bacteriocin production by using Plackett-Burman design.
A quadratic polynomial model for describing the effects of the four factors on bacteriocin activity against Bacillus pumilus CMCC
63202 was obtained by Box-Behnken design. The optimal levels of these factors were found to be K2HPO4 1.89 g/L, cabbage juice
341.5 mL/L, inoculum concentration 3.56% (V/V) and pH 6.95. Under these conditions, the maximum antimicrobial activity was
achieved, which was over 30% higher than that before optimization.

Key words: food-based medium, optimization, response surface methodology, Lactobacillus plantarum 163