Application of a stir-tank bioreactor for perfusion culture and continuous harvest of Glycyrrhiza inflata suspension cells

Abstract

We developed a perfusion stir-tank bioreactor that allowed continuous cultivation and harvest of plant cells and challenged for Glycyrrhiza inflata cell suspensions. Continuous separation of cell cultures from the medium occurred using a gravitational sedimentation column. We then conducted cell retention studies of this bioreactor by detecting the cell loss in the discarded medium. We determined that complete cell retention had been achieved when the perfusion rate (perfusion rate is the ratio of
medium feeding volume per day to bioreactor working volume) was lower than 100% d-1 and the cell suspension recirculation speed was more than 0.5 ml s-1. Growth kinetic measurements showed that the maximum cell concentration reached 25 ± 0.5 g l-1 DW (dry weight). The maximum growth rate occurred on Day 18. Under the given perfusion medium feed rate, the bioreactor operated smoothly, maintaining a relatively stable concentration of 20 g l-1 through continuous cell harvest. The bioreactor
we used could be an efficient cell culture system and demonstrates industrial potential.