Characterization of cell wall components of wheat straw following hydrothermal pretreatment and fractionation.
Thermophysical pretreatment enhances the enzymatic hydrolysis of lignocellulose. However, its impact on cell wall chemistry is still poorly understood. This paper reports the effects of hydrothermal pretreatment on the degradation and alkali-extractability of wheat straw cell wall polymers. Pretreatment resulted in loss and/or solubilization of arabinoxylans (by 53%), ferulic and diferulic acids which are important cross-linking agents accompanied by concomitant increases in cellulose (up to 43%) and lignin (29%). The remaining water-insoluble hemicelluloses were more readily extractable in alkali and were reduced in molecular weight indicating substantial thermochemical depolymerization. They were also associated with smaller but significant amounts of (cellulose-derived) glucose. The alkali-insoluble residues consisted predominantly of cellulosic glucose and lignin and contained p-coumaric acid. The depolymerization of hemicelluloses, reduction in cinnamic acids and partial degradation of cellulose is likely to contribute significantly to the accessibility of cellulases during subsequent enzymolysis.
The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
Zara
Z
Merali
Justin D
JD
Ho
Samuel R A
SR
Collins
Gwénaëlle
G
Le Gall
Adam
A
Elliston
Andres
A
Käsper
Keith W
KW
Waldron
D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry*; D002482:Cellulose / Q000032:analysis*; D005947:Glucose / Q000032:analysis*; D006358:Hot Temperature; D008031:Lignin / Q000032:analysis*; D035261:Plant Components, Aerial / Q000737:chemistry* / Q000166:cytology; D014908:Triticum / Q000737:chemistry* / Q000166:cytology; D014867:Water / Q000737:chemistry*
D014867:Water; D002482:Cellulose; D008031:Lignin; D005947:Glucose