Efficient resveratrol production by immobilized β-glucosidase on cross-linked chitosan microsphere modified by l-lysine

Resveratrol and its glycosidic derivative polydatin are the major stilbenes in Polygonum cuspidatum, a most widely used traditional herbal medicine. To produce resveratrol via enzymatic hydrolysis of polydatin, beta-glucosidase was immobilized on cross-linked chitosan microspheres modified by L-lysine. The condition of enzyme immobilization was optimized, and the characterization of the immobilized enzyme was carried out. K-m value of immobilized beta-glucosidase was calculated as 47.7 +/- 0.7 mM, and V-max value was 34.6 +/- 0.5 U/mg. Under optimized condition, which was 45 degrees C, pH 6.0, with the initial polydatin concentration of 2.0%, and the flow rate of 1.0 mL/min, the overall hydrolysis yield could reach 85.8 +/- 0.6%, and the activity of the immobilized enzyme remained 92.2 +/- 0.9% after continuous hydrolysis for 8 h. Enzymatic hydrolysis of polydatin extracted from P. cuspidatum is a promising method to increase the supply of resveratrol in pharmaceutical markets worldwide, which also showed a new application of immobilized beta-glucosidase in biotechnological industry. (C) 2014 Elsevier B.V. All rights reserved.