Effects of potassium ion on cell growth and production of ginseng saponin and polysaccharide in suspension cultures of Panax ginseng

Abstract

The effects of initial K + concentrations (0–60 mM) on the kinetics of cell growth, nutrients metabolism and production of ginseng saponin and polysaccharide in suspension cultures of Panax ginseng were studied by altering KNO 3 and NaNO 3 concentrations at 60 mM of total nitrate (as the sole nitrogen source). The results show that more soluble sugar was stored within the cells under K +-deficiency, and a curvilinear relationship between initial K + concentration and the active biomass accumulation (which was the total cell mass minus intracellular soluble sugars) was found. The K + consumption by the cells was dependent on the intial medium K + and there was a linear correlation between K + consumption and nitrate consumption. Furthermore, our results indicate that although K + had little effect on the content of ginseng polysaccharide, the saponin content was remarkably enhanced with increase of initial K + within 20–60 mM. The highest saponin production of 730 mg 1 −1 was achieved at an initial K + concentration of 60 mM.