Promotional effects of water-soluble extractives on bamboo cellulose enzymolysis

Abstract

The release of fermentable monosaccharides from cellulose is a key step for the economical and efficient production of ethanol from lignocellulosic biomass. However, some residual substances in pretreated biomass negatively affect enzymolysis by reducing the activity of the enzyme due to the nonproductive and competitive binding of enzymes. To improve enzyme efficiency, heterologous proteins have been introduced as an additive for cellulase during the hydrolysis process. In this study, the enzymatic hydrolysis of cellulose from pretreated bamboo was enhanced by adding an aqueous extract of the bamboo to the hydrolysis system. The cellulose to glucose conversion yield (CGCY) increased to different extents when different substrates were used with different enzyme loadings. The promotional effect of bamboo extractives on enzymatic hydrolysis of different bamboo varieties was observed. In conclusion, the deactivation of the cellulolytic enzyme by negative binding to residual lignin in substrate was reduced due to the competitive effects of proteins in the extract. In addition, other effects, such as easy accessibility of the substrate (amorphogenesis), were also possible reasons. Overall, the promotional effect of bamboo aqueous extractives played an important role in the enzymatic hydrolysis of pretreated bamboo.