Ginsenoside Compound K Production from Ginseng Root Extract by a Thermostable β-Glycosidase from Sulfolobus 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 12h by 40U/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 Re, 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 Re -> compound Mc -> compound K.