Adsorption of Trichoderma reesei Cellulase on Softwood Lignin-based Lignophenol

Abstract

Lignophenol is a lignin-based polymer which highly conserves the native lignin structure. Through simple adsorption experiments between Trichoderma reesei cellulase and softwood lignophenol synthesized from Hinoki cypress and p-cresol, several ideas were obtained on non-productive cellulase binding to lignin expected during enzymatic saccharification of cellulosic substrates. Cellulase is promptly bound to lignin within 10 min. The adsorption reaches a saturated value, indicating that cellulase adsorption on lignin is not multi-layered. Maximum adsorption is observed at around the isoelectric point of cellulase and, at the same time, phenolic hydroxyl groups in lignin seem to enhance cellulase binding. Cellulase bound to lignin maintains its enzymatic activity and probably functions as an immobilized cellulase in saccharification liquor.