Optimization of solid-state fermentation conditions with Jerusalem artichoke powder for production of inulinase by Aspergillus niger

To obtain inulinase with high activity and low cost,optimization of medium composition and fermentation conditions for the production of inulinase by Aspergillus niger A4 was investigated in solid-state fermentation using orthogonal experimental designs.The results showed that with solid-state fermentation method,when the fermentation temperature was 35℃,wheat bran 28%,Jerusalem artichoke powder 12%,the initial pH7.0,inoculum 3%,(NH4)H2PO4 0.5%,corn steep 1%,fermentation time 6d,the enzyme activity was up to 158U/g solid medium,which was much higher than that reported in the literature using liquid fermentation.