CP/MAS 13C NMR analysis of cellulase treated bleached softwood kraft pulp

Fully bleached softwood kraft pulps were hydrolyzed with cellulase (1,4-(1,3:1,4)-beta-D-glucan 4-glucano-hydrolase, EC 3.2.1.4) from Trichoderma reesei. Supra-molecular Structural features of cellulose during enzymatic hydrolysis were examined by using CP/MAS C-13 NMR spectra in combination with line-fitting analysis. Different types of cellulose allomorphs (cellulose I alpha, cellulose I-beta, para-crystalline) and amorphous regions were hydrolyzed to a different extent by the enzyme used. Also observed was a rapid initial phase for hydrolysis of regions followed by it slow hydrolysis phase. Cellulose I-alpha, para-crystalline, and non-crystalline regions of cellulose are more susceptible to enzymatic hydrolysis than cellulose I-beta during the initial phase. After the initial phase, all the regions are then similarly susceptible to enzymatic hydrolysis. (c) 2006 Elsevier Ltd. All rights reserved.