Induction and Optimization of Ghitosanase Production by Aspergillus fumlgatus YT-1 Using Response Surface Methodology

摘要

With the use of a mixture of shrimp shell powder and wheat bran as carbon sources in the medium, statistical methods including Plackett-Burman design (PBD). steepest ascent method and Central composite design (CCD) were applied to optimize chitosanasc production by a newly isolated Aspergillus fumigatus YT-1 under submerged fermentation. Significant factors for chitosanase production including (NH4)2SO4, shrimp shell powder and MgSO4 ·7H2O were screened. Maximum chitosanase activity (21.85 U mL~(-1)) was achieved under the optimized conditions [(NH4)2SO4 5.05 g L~(-1), shrimp shell powder 23.40 g L~(-1), MgSO4 ·7H2O 0.88 g L~(-1)]. According to maximum chitosanase activity (5.29 U mL~(-1)) which was obtained under unoptimized conditions, optimization resulted in an overall 3.13-fold enhancement in chitosanase activity. The optimal temperature and pH for chitosan hydrolysis were 60 °C and pH 4.8, respectively.