Optimization of Alkali-catalyzed Pretreatment for the Production of Fermentable Sugars from Wheat Straw: a Response surface Approach

Abstract

This study used wheat straw as a feedstock for fermentable sugar liberation. To study and improve the outcome of fermentable sugar production factors, including NaOH concentration (0.25– 2.25 w/w%), substrate concentration (5–35%), and autoclave time (10–50 min), on sugar concentration, response surface methodology (RSM) based on the central composite design (CCD) was used. The optimized pretreatment (1% (w/v) substrate, 1.0% (w/v) sodium hydroxide, and 30 (min) autoclaving times at 121°C) decreased lignin content by 63.09% (w/w) and boosted accessible cellulose content (46.48% w/w) compared to untreated biomass, as confirmed by compositional analyses of pretreated biomass. Following statistical optimization utilizing response surface methods, the enzymatic hydrolysis rate was enhanced by 2.08-fold (504.6mg/g substrate after 12 h of enzymatic hydrolysis was considerably greater than the control, 156.26 ± 0.05mg/g substrate). Our findings emphasize the potential of wheat straw biomass as a promising source of raw materials for bioethanol production.