Cell densities were measured at 525 nm after diluting cells from 0.05 to 0.5 optical density (OD). An OD of 1.0
was equivalent to 0.21 mg dry weight of cells/ml. Ethanol was separated by gas chromatography (Jeffries,
1982). Sugars and other fermentation byproducts were determined by high performance liquid chromatography
(HPLC) (Verhaar and Kuster, 1981). The amounts of hexoses and pentoses in the wood hydrolyzate samples,
such as glucose, galactose, mannose, and xylose, were determined by HPLC and expressed as total fermentable
sugars. The amount of arabinose quantified in the wood hydrolyzate was expressed separately.