Integrated chemical and multi-scale structural analyses for the processes of acid pretreatment and enzymatic hydrolysis of corn stover. (5th May 2016)

• Record Type: Journal Article
• Authors: Chen, Longjian; Li, Junbao; Lu, Minsheng; Guo, Xiaomiao; Zhang, Haiyan; Han, Lujia
• Is Part Of: Carbohydrate polymers. Volume 141(2016)
• Page Start: 1
• Page End: 9
• Publication Date: 2016-05-05
• Subjects: Acid pretreatment -- Chemical analysis -- Corn stover -- Enzymatic hydrolysis -- Structural analysis; Polysaccharides -- Periodicals; Polysaccharides -- Periodicals; Polysaccharides -- Périodiques; Electronic journals; 547.78
• DOI: 10.1016/j.carbpol.2015.12.079
• Languages: English
• ISSNs: 0144-8617

Abstract

Graphical abstract: Highlights: Both acid pretreatment (AP) and enzymolysis (EL) of corn stover were characterized. AP decreased hemicellulose from 19.7% in raw substrate to 9.28%. AP increased pore volume from 0.0067 cm 3 /g in raw substrate to 0.019 cm 3 /g. Enzyme adsorption in AP substrate was three-fold higher than that in raw substrate. EL proceeded in the parallel hydrolysis mode of crystalline/amorphous cellulose. Abstract: Corn stover was pretreated with acid under moderate conditions (1.5%, w/w, 121 °C, 60 min), and kinetic enzymolysis experiments were performed on the pretreated substrate using a mixture of Celluclast 1.5 L (20 FPU/g dry substrate) and Novozyme 188 (40 CBU/g dry substrate). Integrated chemical and multi-scale structural methods were then used to characterize both processes. Chemical analysis showed that acid pretreatment removed considerable hemicellulose (from 19.7% in native substrate to 9.28% in acid-pretreated substrate) and achieved a reasonably high conversion efficiency (58.63% of glucose yield) in the subsequent enzymatic hydrolysis. Multi-scale structural analysis indicated that acid pretreatment caused structural changes via cleaving acetyl linkages, solubilizing hemicellulose, relocating cell wall surfaces and enlarging substrate porosity (pore volume increased from 0.0067 cm 3 /g in native substrate to 0.019 cm 3 /g in acid-pretreated substrate), thereby improving the polysaccharide digestibility.