Batch Cultures of Somatic Embryos of Digitalis lanata in Gaslift Fermenters. Development and Cardenolide Accumulation

Abstract

Somatic embryos of Digitalis lanata strain VII were successfully grown as batch cultures in gaslift fermenters. Embryo development and formation of cardenolides in the embryos resembled those of cultures grown in shake flasks. Both processes depended on the developmental stage of the embryos at the time point of inoculation, the homogeneity of the embryo structures, the density of the inoculum, the composition of the nutrient medium, the intensity of irradiation, and the composition of the gas mixtures used for agitation of the embryo suspension. The cultures contained 0.7&-1.0 (µ,mol digitoxin equivalents g^-1 dry wt. (2.6-6.5 µmol digitoxin equivalents l^-1) after a cultivation period of 28 d.

Key words

Digitalis lanata - embryo culture - gaslift fermenters - cardenolide formation - gas mixture