Production of rosmarinic acid in high density perfusion cultures ofAnchusa officinalis using a high sugar medium

Summary The most direct approach to enhancing the volumetric yield of secondary metabolites in plant tissue cultures is to operate the culture under high cell density. In this study, a cell suspension ofAnchusa officinalis was cultivated using a semi-continuous perfusion technique, i.e. batch cultivation with intermittent medium exchange. Using a perfusion medium containing sucrose concentration which was two times that in the normal growth medium, the final cell density and the final product concentration were increased by more than 2-fold compared with a batch culture without medium exchange. The high cell density obtained from the semi-continuous perfusion culture can be explained by the prevention of nutrient depletion, removal of toxic by-products, as well as the control of cell size by virtue of the high sugar medium osmolarity.