Effect of supramolecular structural changes during the crystalline transformation of cellulose on its enzymatic hydrolysis

Abstract

Currently, the main problems in cellulose conversion to glucose are the low enzymatic hydrolysis efficiency and the high cellulase cost. In this study, cellulose I allomorph substrates were from p-toluenesulfonic acid (PT), dilute sulfuric acid (DA) and sulfite (SP) treated cellulose substrates, and cellulose II allomorph were prepared by mercerization. XRD, NMR, FTIR and molecular docking were used to investigate the effect of cellulose allomorphs on hydrolysis efficiency. The results showed that cellulose II allomorph had a lower cellulase adsorption capacity and higher hydrolysis efficiency. This was because cellulose II allomorph owned gt conformation, and less tg and gg conformations of C-6 hydroxymethyl, causing the reduction of interchain hydrogen bonds and the increase in hydrolysis efficiency (PT, DA and SP: from 62.04%, 65.62% and 63.21% to 83.23%, 89.24% and 87.65%, respectively). This study provided theoretical supports for further understanding the effect of cellulose allomorphs on enzymatic hydrolysis.