Design of a thermoregulated phase-separable system for homogeneous enzymolysis of cellulose

Abstract

A polyether-substituted cellulase (Cell-Mal) has been synthesized by the site-specific modification of free cysteine residues (–SH) in commercial natural cellulase. Cell-Mal allows the homogeneous enzymolysis of cellulose and self-thermoregulated separation in NaOH/urea solution, in which different kinds of cellulose are highly soluble but natural cellulase is swiftly deactivated. The modification process is simple and Cell-Mal shows high activity and thermosensitivity in the NaOH/urea solution. Significantly, Cell-Mal could hydrolyze all kinds of cellulose into glucose with a high yield within 24 h at 30 °C in a homogeneous alkaline system. Furthermore, Cell-Mal was automatically separated from the reaction system on cooling to below −10 °C. This system provides a potential method for environmentally benign and effective utilization of cellulose.