Ginsenoside Compound K Production from Ginseng Root Extract by a Thermostable β-Glycosidase fromSulfolobus solfataricus

Ginsenoside compound K was produced from ginseng root extract using a thermostable recombinant beta-glycosidase from Sulfolobus solfataricus. The pH and temperature for maximum production were 5.5 and 90 degrees C. The half-lives of the enzyme were 66, 30, and 1.7 h at 80, 85, and 90 degrees C respectively. The ginsenoside-hydrolyzing activity (Rd>Rb(1)>Rc>Rb(2)) and compound K-producing activity (Rd>Rc>Rb(1)>Rb(2)) of the beta-glycosidase were also determined. At pH 5.5 at 85 degrees C, 1.63 mg/ml of compound K was produced within 12 h by 40 U/ml of enzyme from 1.9 mg/ml of ginsenoside Rb(1), 0.52 mg/ml of ginsenoside Rb(2), 0.92 mg/ml of ginsenoside Rc, and 0.23 mg/ml of ginsenoside Rd in a 10% (w/v) ginseng root extract via two transformation pathways, Rb(1) or Rb(2) --> Rd --> F(2) --> compound K, and Rc --> compound Mc --> compound K.