6-19: Evaluation of the inhibitive effect of lignin on cellulase using a novel lignin isolation method based on phase separation

Non-productive cellulase adsorption on lignin has been recently paid attention to in the enzymatic hydrolysis of lignocellulosic biomass. In this study, lignins were separated from lignocellulosic biomass by a novel lignin isolation method based on phase separation using 72% H₂SO₄ and p-cresol. Cellulase derived from Trichorderma reesei was incubated with the isolated lignins. Cellulase was promptly adsorbed on lignin to the maximum capacity. Beta-glucosidase tended to be slightly released from the lignin in fresh buffer, however, the adsorbed cellulase was basically hard to be detached from lignin. Therefore, the adsorbed cellulase behaves like an immobilized cellulase to perform hydrolysis of cellulose. The enzymatic activity of the cellulase was measured for hydrolysis of sodium carboxymethyl cellulose, a filter paper and other cellulosic substrates. The life and the reusability of the cellulase were discussed. Our results could potentially give information about how the lignin-binding cellulase functions in saccharification liquor and how it could be reused or recycled.