Synergistic mechanism of steam explosion combined with fungal treatment by Phellinus baumii for the pretreatment of corn stalk

Pretreatment was the essential step for industrial application of lignocellulosic biomass. Combination of steam explosion and fungal treatment was conducted, and synergistic mechanism of the combined pretreatment was evaluated in terms of pore size distribution, crystallinity index, chemical compositions and enzymatic hydrolysis. The results showed that steam explosion destroyed the rigid structure of corn stalk, increased pore size and porosity, and exposed crystalline component of cellulose. Steam explosion broke the lignin-carbohydrate-complex structure of lignocellulosic biomass and facilitated the fungal treatment. Phellinus bawnii could selectively degrade 34.7% and 36.58% of lignin for 1.4 MPa and 1.7 MPa steam-exploded corn stalk, respectively. As a result, the highest glucose yield of corn stalk pretreated by the condition of 1.7 MPa steam explosion associated with 21 d P. baumii reached 313.31 g kg(-1), which was 2.88 and 1.32 times higher than that of the untreated corn stalk and the 1.7 MPa steam-exploded corn stalk, respectively. The combined pretreatment enhanced the enzymatic hydrolysis, which was a promising technology that might be explored as alternative to the existing pretreatment. (C) 2014 Elsevier Ltd. All rights reserved.