1 Department of Chemical and Biochemical Engineering, Technical University of Denmark2 Center for BioProcess Engineering, Department of Chemical and Biochemical Engineering, Technical University of Denmark3 University of Copenhagen4 Department of Systems Biology, Technical University of Denmark5 Department of Civil Engineering, Technical University of Denmark
Biological degradation of biomass on an industrial scale culminates in high concentrations of end products. It is known that the accumulation of glucose and cellobiose, end products of hydrolysis, inhibit cellulases and decrease glucose yields. Aside from these end products, however, other monosaccharides such as mannose and galactose (stereoisomers of glucose) decrease glucose yields as well. NMR relaxometry measurements showed direct correlations between the initial T 2 of the liquid phase in which hydrolysis takes place and the total glucose production during cellulose hydrolysis, indicating that low free water availability contributes to cellulase inhibition. Of the hydrolytic enzymes involved, those acting on the cellulose substrate, that is, exo- and endoglucanases, were the most inhibited. The β -glucosidases were shown to be less sensitive to high monosaccharide concentrations except glucose. Protein adsorption studies showed that this inhibition e ff ect was most likely due to catalytic, and not binding, inhibition of the cellulases.
Journal of Agricultural and Food Chemistry, 2014, Vol 62, p. 3800-3805
Water availability; Enzymatic hydrolysis; T 2 relaxation; Cellulase adsorption; Cellulase inhibition