Optimization of solid-state medium for the production of inulinase by Aspergillus ficuum JNSP5-06 using response surface methodology

In the present study, response surface methodology (RSM) was employed to optimize the composition of medium based on Plackett-Burman design and Box-Behnken design for the production of inulinase by Aspergillus ficuum JNSP5-06 using solid-state fermentation (SSF). Inulin, NH4H2PO4 and corn steep liquor were found to have significant effects on inulinase production by the Plackett-Burman design. The concentrations of the three compositions above were further optimized using a Box-Behnken design. The results showed that the final concentration of medium optimized with RSM was 11.47% inulin, 0.76% NH4H2PO4 and 5.71% corn steep liquor by employing wheat bran as the solid substrate. Under optimized medium, the average inulinase activity reached 205.63 U/g initial dry substrate.