Application of β-glucosidase Immobilized on Chitosan microspheres in Degradation of Polydatin in Polygonum cuspidatum

Abstract

Resveratrol in Polygonum cuspidatum is a β-glycoside, which can be hydrolyzed to resveratrol by β-glucosidase. it is an efficient production process to degrade polydatin from Polygonum cuspidatum extract by immobilized β-glucosidase. It is of great significance to explore suitable immobilization conditions to improve the catalytic efficiency and reusability of β-glucosidase for polydatin degradation and cost reduction. In this paper, the recombinant Escherichia coli bgl2238, which was screened and constructed from corn soil of Heilongjiang Province in the early laboratory, was immobilized by chitosan adsorption and glutaraldehyde crosslinking. The preparation conditions and immobilization process of bgl2238 were determined by single factor method: the optimal crosslinking time was 1 h, the optimal crosslinking temperature was 20 °C, the recovery rate of enzyme activity of bgl2238 was 87 %, and the enzyme activity was 859.65 mU/g. The optimum temperature of the immobilized bgl2238 is 50 °C, which is 6 °C higher than that of the free bgl2238, and the temperature stability and pH stability are improved. After six consecutive hydrolysis of Polygonum cuspidatum, the degradation rate of polydatin is still over 70 %, which proves that the immobilized bgl2238 has good reusability. This will be helpful to evaluate the application prospect of β - glucosidase immobilized in this system and determine the best conditions for its production.