摘要

In this study, a simple, inexpensive and fast beta-glucosidase immobilization system was constructed and evaluated in isoflavone glycosides hydrolysis. A beta-glucosidase gene from Thermoascus aurantiacus IFO9748 was recombinantly expressed in Pichia pastoris KM71H and immobilized on regenerated amorphous cellulose (RAC) by fused cellulose binding module 3. Through simple mixing cellulose and crude enzyme for 15 min under room temperature, 96.04% beta-glucosidase was immobilized onto RAC. The optimum temperature for beta-glucosidase activity was increased by 5AC after immobilization. The half-life (tA 1/2) of heat inactivation of immobilized enzyme at 60oC was improved over 8 folds. After 30 rounds recycled at 40oC, 96.9% daidzin and 98.9% genistin could still be hydrolyzed. A continuous hydrolysis system was also constructed, and at the flow rate of 0.2 mL/min after 30 h hydrolysis, 95.6% genistin and 90.2% daidzin can still be hydrolyzed. Combined the simple and high efficient enzyme immobilization procedure and inexpensive cellulose, this scalable and practical system may have broad prospects for industrial utilization.