Comparative study of different alcoholate pretreatments for enhanced enzymatic hydrolysis of sugarcane bagasse

Abstract Pretreatment of sugarcane bagasse (SCB) with alcoholates, sodium methoxide (CH 3 ONa), potassium methoxide (CH 3 OK) and sodium ethoxide (C 2 H 5 ONa), was investigated. Analyses of lignocellulose composition and enzymatic saccharification indicated that C 2 H 5 ONa showed the highest enzymatic efficiency of 102.1%. The response surface optimization of C 2 H 5 ONa pretreatment showed that under optimal conditions (4% of C 2 H 5 ONa, 121 °C, 1 h), 65.4% of lignin was removed and the enzymatic efficiency reached 105.2%. Hydrolysis of SCB with cellulases and xylanase at a ratio of 4:1 showed the strongest synergism with reducing sugar production of 21 g/L and conversion rates of cellulose and xylan reaching 110.4% and 94.5%, respectively. These results indicated that C 2 H 5 ONa is a promising alkali to pretreat SCB and the synergism between cellulases and xylanase has a significant effect on enzymatic saccharification of the pretreated SCB.