Importance of cellulase cocktails favoring hydrolysis of cellulose

Abstract

Depolymerization of lignocellulosic biomass is catalyzed by groups of enzymes whose action is influenced by substrate features and the composition of cellulase preparation. Cellulases contain a mixture of variety of enzymes, whose proportions dictate the saccharification of biomass. In the current study, four cellulase preparation varying in their composition were used to hydrolyze two types of alkali-treated biomass (aqueous ammonia-treated rice straw and sodium hydroxide-treated rice straw) to study the effect on catalytic rate, saccharification yields, and sugar release profile. We found that substrate features affected the extent of saccharification but had minimal effect on the sugar release pattern. In addition, complete hydrolysis to glucose was observed with enzyme preparation having at least a cellobiase units (CBU)/carboxymethyl cellulose (CMC) ratio (>0.15), while a modified enzyme ratio can be used for oligosaccharide synthesis. Thus, cellulase preparation with defined ratios of the three main enzymes can improve the saccharification which is of utmost importance in defining the success of lignocellulose-based economies.

Exploration of mechanisms of lignin extraction by different methods

“…17 Under acidic treatment, the breakage of bonds occurs on aryl ether linkages (mainly β-O-4 linkages) of lignin, 18 ultimately leaving acid-insoluble lignin precipitating in the form of residue. 19 Commonly used acids include H 2 SO 4 , H 3 PO 4 , HI, HF, or CO 2 gas. 18,20 It is worth mentioning that the extraction effect of mixed acids is significantly better than that of single acid as well as a much more higher purity of obtained lignin.…”

“…Acids solubilize the hemicellulose polysaccharide matrix and cellulose 17 . Under acidic treatment, the breakage of bonds occurs on aryl ether linkages (mainly β‐O‐4 linkages) of lignin, 18 ultimately leaving acid‐insoluble lignin precipitating in the form of residue 19 . Commonly used acids include H 2 SO 4 , H 3 PO 4 , HI, HF, or CO 2 gas 18,20 .…”