“…Photoperiod-sensitive (PS) sorghum, due to its advantages of drought tolerance, relatively low lignin content, and high soluble sugar content, is a promising biomass source for bioethanol production (Xu et al, 2011a). Pretreatment is a crucial step in biomass-ethanol conversion; its goals are to break the lignin/hemicellulose seal, disrupt the crystalline structure of cellulose, and increase the total surface area of cellulose to make the polysaccharides more susceptible to enzyme hydrolysis (Mosier et al, 2005;Whitfield et al, 2012). Numerous pretreatment methods have been employed for biomass processing, such as steam explosion, dilute acid, alkali, ammonia fiber explosion, and supercritical CO 2 (Wu et al, 2011).…”