Bioethanol Production by Pichia stipitis from Enzymatic Hydrolysates of Corncob-based Spent Mushroom Substrate

The potential of spent mushroom substrate after cultivation of Pleurotus eryngii as a biomass resource for bioethanol production was investigated. Materials were pretreated by ball milling for 1 h, and enzymatic hydrolysis was then carried out. Glucose, xylose, arabinose and galactose were detected in enzymatic hydrolysates, and a > 59.0% yield of total sugars was obtained, even at a substrate concentration of 30% (w/v). Enzymatic hydrolysates were fermented using Pichia stipitis. When enzymatic hydrolysates obtained from a 20% (w/v) substrate concentration were fermented, the maximum ethanol concentration was 17.7 g and ethanol yield was 67.0%. These results indicate that corncob-based spent mushroom substrate can be used as a raw material for bioethanol production.