Fermentation profiles. Glucose (blue), xylose (red), and ethanol (green) concentrations achieved during fermentation of switchgrass. All fermentations were performed using Saccharomyces cerevisiae at 30°C and shaken at 150 rpm. Switchgrass hydrolysate after 72 h of enzymatic hydrolysis at 20% solid loading was used except for the October harvest of Alamo switchgrass, where the solid loading was 10%. Data points are the average of duplicate fermentations.