a process for producing ethanol from plant biomass is disclosed . the process in cludes forming a substrate from the biomass with the substrate including hydrolysates of cellulose and hemicellulose . a species of the fungus paecilomyces , which has the ability to ferment both cellobiose and xylose to ethanol , is then selected and isolated . the substrate is inoculated with this fungus , and the inoculated substrate is then fermented under conditions favorable for cell viability and conversion of hydrolysates to ethanol . finally , ethanol is recovered from the fermented substrate .