The chemical compositions of the original and pretreated bio- mass were analyzed by the Analytical and Microscopy Laboratory of the Forest Products Laboratory [24,26]. Ethanol analysis in the cellulosic substrate fermentation broth was carried out using a gas chromatograph (GC, model 7890, Agilent Technologies, Palo
Alto, CA) through direct sample injection using an external stan- dard for calibration. The sample was centrifuged and the superna- tant was filtered before injection to the GC column. The GC is equipped with a flame ionization detector and Agilent DB Wax col- umn of 30 m with an ID 0.32 mm. A universal guard column was used to reduce column contamination. Inhibitor concentrations in the pretreatment hydrolysates were measured using an HPLC equipped with an EconosphereTM C18 column (5-lm particle size, 250 mm