Eileen Stieglitz - Wynnewood PA,
Paul V Viitanen - West Chester PA,
Barry Stieglitz - Wynnewood PA,
E I du Pont de Nemours and Company - Wilmington DE
Xylose-utilizing, ethanol producing strains of with improved performance in medium comprising biomass hydrolysate were isolated using an adaptation process. Independently isolated strains were found to have independent mutations in the same coding region. Mutation in this coding may be engineered to confer the improved phenotype.