Eastern gamagrass as an alternative cellulosic feedstock for bioethanol production

Eastern gamagrass (Trypsacum dactyloides) is a C4 perennial grass, native to the USA with desirable characteristics that warrants further investigation as a new lignocellulosic crop for bioethanol production. Chemical composition assays showed that eastern gamagrass had comparable cellulose, hemicellulose and lignin compositions to those of switchgrass (Panicum virgatum). With the cellulose solvent-based lignocellulose fractionation (CSLF) pretreatment and subsequent enzymatic saccharification, 80.5–99.8% of cellulosic glucose was released from the gamagrass biomass, which was 10–17% greater than the glucose release efficiency from switchgrass (73.5–87.1%). Furthermore, the hydrolysate of gamagrass supported greater ethanol fermentation yield (up to 0.496 g/g glucose) than the hydrolysates of switchgrass. As such, in the whole process of biomass-to-ethanol conversion, gamagrass could yield 13–35% more ethanol per gram of biomass than switchgrass, indicating that gamagrass has high potential as an alternative energy feedstock for lignocellulosic ethanol production.

► A C4 perennial plant, eastern gamagrass was investigated as an alternative lignocellulosic crop for bioethanol production. ► The biomass of eastern gamagrass was less recalcitrant to enzymatic saccharification than the biomass of switchgrass. ► Eastern gamagrass could yield 13–35% more ethanol per gram biomass than switchgrass.