The inoculum size triggers tryptamine or secologanin biosynthesis in a Catharanthus roseus cell culture

A Catharanthus roseus cell line was characterized for the accumulation of s ecologanin, tryptophan, tryptamine, strictosidine and ajmalicine, as well a s for the activities of the enzymes geraniol 10-hydroxylase, tryptophan dec arboxylase and strictosidine synthase. The effects of the inoculum size on these parameters were discussed. The increase of the inoculum size from 40- 160 g of fresh weight per liter of medium favored the accumulation of secol oganin and alkaloids. A coordinated regulation of geraniol 10-hydroxylase a nd tryptophan decarboxylase by inoculum size seems to contribute to the eff ects observed. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.