Effect of sugar concentration on ginsenoside biosynthesis in hairy root cultures of Panax quinquefolium cultivated in shake flasks and nutrient sprinkle bioreactor

The study assessed the influence of sugar concentration (10, 20, 30, 50, 70, 100, 120 g l(-1)) on growth and ginsenoside biosynthesis in Panax quinquefolium hairy roots cultivated in shake flasks and a nutrient sprinkle bioreactor. The highest growth rate was achieved in medium containing 3-5 % sucrose. More than 70 g l(-1) or less than 20 g l(-1) sugar content in the medium induces significant inhibition of root growth when cultivated in shake flasks. The saponin content was determined using HPLC. The maximum yield (above 9 mg g(-1) d.w.) of the sum of six examined ginsenosides (Rb-1, Rb-2, Rc, Rd, Re and Rg(1)) in hairy roots cultivated in shake flasks was obtained with 30 g l(-1) sucrose in the medium. The sucrose concentration in the medium was found to correlate with saponin content in bioreactor-cultured specimens. A higher level of protopanaxadiol derivatives was found for lower (20 and 30 g l(-1)) sucrose concentrations; higher sucrose concentrations (50 and 70 g l(-1)) in the medium stimulated a higher level of Rg group saponins.