Gamagrass varieties as potential feedstock for fermentable sugar production

► Gamagrass had a higher carbohydrate content than switchgrass and Bermuda grass. ► Biochemical conversion of gamagrass resulted in high sugar yields. ► Gamagrass is a promising feedstock for biofuels. To evaluate the potential of gamagrass as a feedstock for biofuels, seven gamagrass varieties were analyzed for their chemical composition and subjected to pretreatment at 121°C using 1% NaOH/H2SO4 (w/w) for 60min and enzymatic hydrolysis for fermentable sugar production. Based on total sugar yield, the varieties Eagle Point Devil Corn and Sun Devil were selected for NaOH and H2SO4 pretreatment, respectively. The investigation on pretreatment conditions showed that, the conditions applied in gamagrass variety screening (121°C, 1% NaOH/H2SO4, 60min) were sufficient to maximize sugar production, such that the total sugar yield of Eagle Point Devil Corn reached 479.6mgg−1 after NaOH pretreatment and that of Sun Devil reached 456.5mgg−1 raw biomass after H2SO4 pretreatment. Compared with other potential energy crops including switchgrass and Bermuda grass, gamagrass gave a higher sugar yield after NaOH pretreatment and a comparable sugar yield after H2SO4 pretreatment.