Effects of Culture Conditions on Tropane Alkaloid Formation in Hyoscyamus niger Suspension Cultures

Tropane alkaloid formation was studied under various culture conditions in suspension cultures of Hyoscyamus niger L. High aeration increased cell growth and the contents of hyoscyamine and scopolamine. White’s medium inhibited cell growth but increased the hyoscyamine content. The low concentrations of nitrogen and phosphate in White’s medium were responsible for such effects. NAA promoted cell growth but inhibited hyoscyamine formation. A hyoscyamine content of 0.05% dry weight (DW) (0.14 mg in 25 ml of culture medium) was achieved in modified LS medium in which the phosphate concentration was decreased to 0.2 mm and the auxin omitted.

Effects of precursor feeding on alkaloid formation were also studied with the putative precursors of hyoscyamine. N-Methylputrescine, tropine, phenylalanine, and tropic acid increased alkaloid formation, but the promotive effect of these precursors varied from one experiment to another.