A process for increasing the substrate concentration of fermentation broths in the microbiological conversion of cardenolide derivatives

摘要

A process for increasing the substrate concentration of fermentation broths in microbiological conversions of cardenolides having the general formula (I IMAGE [wherein X represents a hydrogen atom or a hydroxy group, and R represents a hydrogen atom or a group of formula (II), (III), (IV) or (V)], IMAGE the said starting substance of the general formula (I) being introduced into the fermentation broth in a solution formed with a water-miscible solvent of electron donor character or with a mixture of such solvents.