Abstract: Single-factor method, Plackett-Burman design and response surface methodology were combinedly used to optimize the fermentation medium composition for naringinase production by Penicillium sp. 1523 at shake flask level. The optimum carbon and nitrogen sources for the growth of Penicillium sp. 1523 were corn meal and bean cake powder, respectively. Using Plackett-Burman design, corn meal, bean cake powder and naringin were screened out of 7 factors as main affecting variables of naringinase production and steepest ascent method was then used to approach their maximum response regions, followed by central composite design, multiple regression analysis and response surface analysis. The optimum medium formula (g/L) determined was composed of corn meal 31.14, bean cake powder 31.53, naringin 1.65, dipotassium hydrogen phosphate 1.00, zinc sulfate 0.10, heptahydrate magnesium sulfate 0.06 and calcium chloride 0.10, and the resulting naringinase activity in fermentation broth reached up to (891.79 ± 6.33) U/mL and was 70.8% higher than before the optimization and consistent with the maximum predicted value.

Key words: naringinase, Plackett-Burman design, response surface methodology, medium optimization