Semicontinuous cultivation of Digitalis lanata cells: Production of β‐methyldigoxin in a 300‐L airlift bioreactor

Abstract
Selected Digitalis lanata cell lines cultivated in 1-L shake flasks or 20-L airlift bioreactors converted β-methyldigitoxin into β-methyldigoxin with almost no side reactions. This biotransformation process was optimized with regard to substrate supply and culture medium composition, and was then scaled up to a volume of 210 L using a 300-L airlift bioreactor. A semicontinuous process was developed in which 513.3 g β-methyldigoxin were produced after 89 days of cultivation.