2.4. Cellobiase production
Cellobiase was produced according to the method of Shen (Shen and Xia, 2004). The solid medium was inoculated with spores suspension of A. niger ZU-07 and cultured at 30 °C for 3 d. The koji produced by solid-state fermentation contained 376 CBU g−1 dry koji and no detectable filter paper activity.