Structural changes in sugarcane bagasse cellulose caused by enzymatic hydrolysis

Abstract

Cellulose I is not completely saccharified to glucose at a low cellulase concentration. In this study, sugarcane cellulose saccharification residues were investigated. Transmission electron microscopy images indicated that the cellulose microfibrils became shorter in the early stages of saccharification and gradually became narrower. The degree of polymerization also decreased in the early stages of saccharification. Cellulose saccharification residues were deuterated by immersing them in deuterium oxide. Infra-red spectra of the deuterated residues indicated that the deuterated hydroxyl group ratio decreased as saccharification progressed. This indicated that cellulose microfibrils were hydrolyzed in their hydrophobic planes by cellulase as if the surfaces were scraped. The increase of hydrophobic planes caused microfibril aggregation, poor accessibility of cellulase to the microfibrils, and a low saccharification rate.

Changes on structural characteristics of cellulose pulp fiber incubated for different times in anaerobic digestate

“…time, since the enzymes present in AD-supernatant will continue degrading and peeling away the glucose units from cellulose fibrils, thereby decreasing nanofiber dimensions and DP (Imai et al, 2020). This statement is confirmed by the estimate of mass loss during the digestate treatment, whose incubation for 5, 10 and 20 days led to mass loss of around 13%, 26% and 55%, respectively, that could directly be correlated with a decrease in DP and therefore, length of the fibers.…”

“…Reports indicate that the amorphous portion of cellulose is degraded more easily by enzymes than the less accessible crystalline regions (Cao and Tan, 2005;Cao and Tan, 2004). As a result, the overall crystalline content of a cellulose substrate increases (until a certain level) with enzyme treatment and, consequently, the cellulose substrate becomes more resistant to further hydrolysis (Imai et al, 2020).…”

Production of Nanocellulose by Enzymatic Treatment for Application in Polymer Composites

“…Cellulose, due to the presence of a large amount of hydrogen bonds in it, is a material whose enzymatic modification requires a synergistic correlation of cellulolytic enzymes [ 31 , 32 , 33 , 34 , 35 ]. Scientists in their works have proved that the effectiveness of this complicated process is influenced not only by the conditions of the hydrolysis reaction, such as temperature, pH of the reaction environment [ 36 ] or the type, activity level and concentration of the selected substrate [ 37 , 38 ], but also the type or degree of polymerization of the cellulose used, its crystallinity and porosity [ 39 , 40 ]. Moreover, it was noticed that the efficiency of the modification process of this polysaccharide is influenced by the dispersion–morphological properties and polymorphism of the selected cellulose material [ 41 , 42 , 43 , 44 ].…”