Optimization of culture conditions for Aspergillus sojae expressing an Aspergillus fumigatus alpha-galactosidase

Using Response Surface Methodology, carbon and nitrogen sources and agitation speed for cultivation of Aspergillus sojae expressing the alpha-galactosidase gene, aglB of Aspergillus fumigatus IMI 385708 were optimized. Compared to cultivation in modified YpSs medium, cultivation in 250-mL Erlenmeyer flasks agitated at 276 rpm and containing 100 mL of optimized medium consisting of 10.5% molasses (w/v) and 1.3% NH4NO3 (w/v), 0.1% K2HPO4, and 0.005% MgSO4 center dot 7H(2)0 achieved a 4-fold increase in alpha-galactosidase production (10.4 U/mL). These results suggest the feasibility of industrial large scale production of an alpha-galactosidase known to be valuable in galactomannan modification