The toxicity of oak and yellow-poplar wood extracts, as well as a firs
t-stage hardwood hydrolyzate liquor prepared from a red oak:white oak:
yellow-poplar (1:1:1) sawdust, on Saccharomyces cerevisiae D5A was exa
mined. Acetone/water and hot methanol extracts of solid biomass sample
s from white oak, red oak, and yellow-poplar gave 88-94% of the ethano
l produced with controls. The organism was tolerant to the compounds p
resent in the xylose-rich hydrolyzate, with fermentation efficiency be
ing improved to 97% of that obtained with controls by using an overlim
ing/thermal conditioning protocol.