Simultaneous production of ginseng saponin and polysaccharide by suspension cultures of Panax ginseng: Nitrogen effects

Abstract

The effects of the nitrogen ( n) source on the kinetics of cell growth, major nutrient consumption, and production of ginseng saponin and polysaccharide in suspension cultures of Panax ginseng cells were studied. The ratio of NO 3 − NH 4 + and initial total medium n were altered. Cell growth was better at 60 m m n and higher ratios of NO 3 − NH 4 + . With nitrate alone or a mixture of nitrate and ammonium (at a ratio of 2:1) provided as n source, 10 m m n was found to be a crucial point for the cell mass accumulation. Nitrate was a favorable n source for ginseng cell growth. A cell growth rate of 0.11 day −1 and a dry cell density of 13 g l −1 were obtained at 10 m m nitrate (sole n source). At an initial ammonium concentration above 20 m m, the ginseng cell growth was inhibited, and a higher intracellular nitrate concentration and lower soluble sugar content in cells were observed. The results also indicate that the specific production ( i.e., content) of ginseng polysaccharide was not significantly affected by the alteration of n source while the maximum production of polysaccharide of 1.19 g l −1 was achieved at NO 3 − NH 4 + of 60:0 under 60 m m of total n ( i.e., sole nitrate). The saponin production was relatively higher within initial n concentrations of 5–20 m m (with nitrate alone or a NO 3 − NH 4 + ratio of 2:1). The highest content (5.2%) and total production (0.6 g l −1) of ginseng saponin were obtained at an initial nitrate of 5 m m.