Enhanced microfibrillation of Miscanthus × giganteus biomass by binary-enzymes pre-treatment

Abstract

Miscanthus, a high yield and low maintenance perennial plant with a high cellulose fiber contents, is a potential feedstock for pulp production. In this study, a binary enzyme cocktail of cellulase and laccase was employed for the extraction of cellulose microfibers from miscanthus biomass. The effect of enzyme concentrations (0.10%, 0.15%, 0.20%, and 0.25%, w/w) for the binary enzymes (cellulase-laccase: 1:1 ratio) pre-treatments on pulp and hand-sheet materials were studied and compared with those prepared from the single enzyme (cellulase or laccase) pre-treatment. The binary enzymes concentration at 0.25% (w/w) showed the maximum extraction yield of cellulose (47.2%, w/w) and lignin (27.9%, w/w). The resulting fibers had 43.7% crystallinity, a degree of polymerization of 1435, a water retention value of 312.7%, and a crystallite size of 23.4 nm. Furthermore, the resulting fibers from binary enzymes concentration at 0.25% (w/w) exhibited a higher thermal stability and fibrillated strands than those obtained from the single enzyme pre-treatment. Hand-sheets developed from the cellulose microfibers extracted by the enzyme cocktail at 0.25% (w/w) enzyme concentration showed higher mechanical properties and water absorption capacity than those prepared from the single enzyme pre-treatment.