Abstract:The effective three-phase statistical method was used to optimize the fermentation conditions for the catalase production by Aeromonas sp.CE-2-A in order to enhance the enzyme activity. The content of maltose，beef extract，calcium chloride and magnesium chloride in fermentation medium was firstly screened with single factor experiment. Based on this, eight factors that affected the enzyme production were evaluated by Plackett-Burman (PB) designing method. It was shown that the medium volume, beef extract content and original pH had great influence on the catalase activity of strain CE-2-A. The effects of three factors on the enzyme activity produced by the strain were observed by Box-Behnken experiment. The result of fermentation optimization was as follows: medium volume 42.6 mL, beef extract content 3.69 g/L, original pH 9.1, and the enzymatic activity of catalase after optimization in shaking flasks was improved from 1849.7 U/mL to 2532.5 U/mL, increasing by 36.9% compared with initial fermentation conditions before the optimization.
