Cellulase immobilized on mesoporous biochar synthesized by ionothermal carbonization of cellulose

Cellulose-based biochar was prepared via ionothermal carbonization of cellulose in [Bmim]Cl with H(2)SO(4)and subsequent pyrolysis. The biochar was analyzed by a series of characterization methods, indicating that it was a kind of mesoporous carbon suitable for the adsorption of cellulase. Kinetic analysis showed that the immobilized cellulase exhibited higher affinity to carboxymethyl cellulose than free cellulase. The immobilized cellulase, at different pH and temperatures, was more stable than free cellulase. It was used to hydrolyze pretreated cellulose in [Bmim]Cl with a total reducing sugar (TRS) yield of 99.9%. The immobilized cellulase maintained activity of 74.8% after five cycles at an immobilized cellulase/cellulose weight ratio of 30:1. When the cellulose loading was increased by a factor of 5, the TRS yield decreased by only 27.5%.