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.