Kinetics of taxol production and nutrient use in suspension cultures of Taxus cuspidata in shake flasks and a Wilson-type bioreactor

Suspension cultures of Taxus cuspidata were grown in shake flasks and Wilson-type reactors where bubbled air provided both agitation and mixing. Taxol titers of 22 mg l-1 were achieved for both configurations in 20 days for a volumetric productivity of 1.1 mg l-1 day-1. This productivity is many-fold higher than reported for other Taxus sp. suspension cultures. Taxol was released to the extracellular medium as it was produced with little intracellular retention (< or = 10%). Taxol production occurred during the last seven days of the cultivation period and was not growth-associated. Although the same taxol titers could be obtained in both reactor types, nutrient uptake rates were faster in the Wilson-type reactor than in shake flasks. Formation of a growth ring in the Wilson-type reactor reduced measured cell mass yields.