Electron beam irradiation enhances the digestibility and fermentation yield of water-soaked lignocellulosic biomass

AbstractIn order to overcome the limitation of commercial electron beam irradiation (EBI), lignocellulosic rice straw (RS) was pretreated using water soaking-based electron beam irradiation (WEBI). This environment-friendly pretreatment, without the formation (or release) of inhibitory compounds (especially hydroxymethylfurfural and furfural), significantly increased the enzymatic hydrolysis and fermentation yields of RS. Specifically, when water-soaked RS (solid:liquid ratio of 100%) was treated with WEBI doses of 1MeV at 80kGy, 0.12mA, the glucose yield after 120h of hydrolysis was 70.4% of the theoretical maximum. This value was predominantly higher than the 29.5% and 52.1% measured from untreated and EBI-treated RS, respectively. Furthermore, after simultaneous saccharification and fermentation for 48h, the ethanol concentration, production yield, and productivity were 9.3g/L, 57.0% of the theoretical maximum, and 0.19g/Lh, respectively. Finally, scanning electron microscopy images revealed that WEBI induced significant ultrastructural changes to the surface of lignocellulosic fibers