PMC

Rate of hydrolysis. Glucose (right) and xylose (left) released during enzymatic hydrolysis between 3 and 168 h of residence time. Pretreatments were performed at the conditions listed in Table 2 and enzyme addition as listed in Table 3. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation.

Box and whisker plot for sugar yields at varying enzyme loadings. Ammonia fibre expansion (AFEX) pretreatment was kept constant for each harvest (conditions listed in Table 2), and enzyme loadings were varied as stated in the text. Hydrolysis was performed at 3% solid loading, 50°C, and 200 rpm rotation, with samples collected after 72 h.

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.

Box and whisker plot for sugar yields at varying pretreatment conditions. Minimum and maximum values, as well as the interquartile range, are shown. Median values are represented by the + sign. Pretreatment conditions were varied as stated in the text. For all data points, hydrolysis was performed at 3% solid loading, 50°C, 200 rpm rotation, and 5 mg Accelerase/g dry biomass, with samples collected after 72 h.