Immobilization of puerarin glycosidase from microbacterium oxydans CGMCC 1788 increases puerarin transformation efficiency

Abstract

For immobilization of puerarin glycosidase from Microbacterium oxydans CGMCC 1788 on DEAE-52 cellulose, the optimal amount of enzyme protein was 12 mg protein: 1 g DEAE-52 cellulose; the optimal pH was 6.5; and the optimal immobilization time was 6 hr. The specific activity of immobilized enzyme was 36.67 mU.g-1 carrier with an immobilization yield of 98.87% and an enzyme recovery yield of 92.43%. The molar transformation rates of puerarin by immobilized enzyme and by the relative bacterial cell amount equal to the same amount of enzyme were 53.3% and 2.2%, respectively, after 1 hr of transformation. The former molar transformation rate, which was similar to that for free enzyme, was more than 24-fold greater than the latter. The immobilized puerarin glycosidase showed improved enzymatic properties and stability. The immobilized puerarin glycosidase retained 88% of its initial activity after being reused 10 times.