ABSTRACT
A high activity isoflavone-glucosidase, which hydrolysis glycosides, was obtainde using liquid fermentation from Absidia sp. R strain. The isoflavone-glucosidase was purified 11 folds with yielding rate of 10.9% after ammonium sulfate precipitation and DEAE-Cellocuse (DE-52) ion exchange chromatography. SDS-PAGE results showed that the molecular weight is 53kD. And the optimum temperature, the optimum pH, Km and pI of the enzyme are 50 deegrees C, 5.0, 1.3 x 10(-2) mol/L and 3.2, respectively. The isoflavone-glucosidase is also rather stable under 60 degrees C and in pH range from 5.0 to 7.0. The enzyme can be activated by Co2+ and Ca2+, and be inhibited by Ag+ and Cu2+.
Subject(s)
Absidia , Glucosidases , Metabolism , Hydrogen-Ion Concentration , Isoflavones , Metabolism , TemperatureABSTRACT
A high active soybean isoflavone glucoside hydrolase-producing mould strain was isolated from spirit qu. Its optimal hydrolase-producing conditions were as follows: 2.5% wheat bran as carbon source, 1% NaNO3 as nitrogen source, initial pH7. 0, culture medium volume 40mL/250mL, inoculating quantity 8% , culture temperature 30℃, revolutions 160r/min and culture time 84h. The enzyme activity reached 82 U/mL. Cu2+ can inhibit Absidia sp. R strain from producing the hydrolase, the influence of other metal ions was not remarkable on it.