Application of response surface methodology to optimize the production of antimicrobial metabolites by Micromonospora Y15

ABSTRACTThe fermentation medium of Micromonospora Y15 was optimized to enhance the production of antimicrobial metabolites with the antimicrobial activity tested against Listeria monocytogenes. First, the optimal medium components (carbon source, nitrogen source and inorganic salt) were determined by the single factor experiment. Second, the Plackett–Burman experiment was used to screen significant factors. Third, the steepest ascent experiment was undertaken to figure out the optimal region of the significant factors. Finally, the central composite experiment was conducted to optimize the final medium components. The single factor experiment results suggested that the optimal medium components were soluble starch, beef extract, peptone, NaCl, K2HPO4, MgSO4, and FeSO4, while the Plackett–Burman experiment demonstrated that beef extract, K2HPO4 and soluble starch were significant factors affecting antimicrobial activity. The steepest ascent experiment results further showed the central point of three signi...