針葉樹および広葉樹リグノクレゾール固定化セルラーゼの特性比較

抄録

Saccharification of cellulosic biomass is essential for the production of bioethanol and other industrial chemicals. The development of an immobilized cellulase is one important alternative to save the cost of cellulase. Until now, various inorganic and organic materials have been tested for the carrier of immobilized cellulases. A lignin-based polymer: lignophenol is also a candidate due to the high protein adsorption capacity via hydrophobic interaction. In this study, two kinds of lignocresols were synthesized from a softwood (Hinoki) and a hardwood (Eucalyptus) with p-cresol and 72% sulfuric acid through the phase separation system. The immobilized cellulases were prepared by simple mixing of Trichoderma cellulase and the lignocresols. The adsorption capacity of Eucalyptus lignocresol for cellulase was lower than Hinoki. It is probably because Eucalyptus lignocresol is rather hydrophilic due to the lower molecular weight and the linear structure with more phenolic hydroxyl groups. The dependences of temperature on the enzymatic activities of the Hinoki and Eucalyptus lignocresol-immobilized cellulases were similar to the native cellulase. While, Hinoki and Eucalyptus lignocresols demonstrated the wider distinct optimum pH range than native cellulase, respectively. Lignocresol-immobilized cellulase successfully hydrolyzed CMC-Na with a small gradual decrease of the enzymatic activity as it was reused repeatedly. The reduction of the enzymatic activity was more pronounced in Eucalyptus than in Hinoki.