초록
Green biotechnology offers a promising approach to convert most of the solid agricultural wastes particularly lignocellulosic biomass into liquid biofuels. In this study, pretreatment of cotton stalk with sodium hydroxide (3% w/v; room temperature for 24h) removed lignin (52.48+/-1.17%) with minimum sugar loss (3.50+/-0.09%). Subsequent two-stage dilute acid hydrolysis of alkali delignified cotton stalk released 29.40+/-0.85g/L sugars with 63.50+/-1.06% holocellulose hydrolysis along with furfurals (1.32+/-0.10g/L) and phenolics (2.18+/-0.15g/L) in the hydrolysate. Detoxification of hydrolysate with overliming and adsorption with activated charcoal caused 59.12% and 78.44% reduction in total furfurals and phenolics, respectively. Batch fermentation of detoxified acid hydrolysate with monoculture and cocultures of Saccharomyces cerevisiae VS3 and Pichia stipitis NCIM3498 showed ethanol production of 6.28+/-0.08g/L, (yield, 0.39g/g); 10.14+/-0.19g/L (yield, 0.45g/g) and 11.64+/-0.32g/L (yield, 0.47g/g), respectively.