A perfusion air-lift bioreactor for high density plant cell cultivation and secreted protein production

Abstract

A new bioreactor design that allows continuous perfusion cultivation of plant cell suspensions is described in this paper. This design incorporates an internal cell settling zone with an external-loop air-lift bioreactor. The settling zone is created by inserting a baffle plate into the upper portion of the downcomer. Using this bioreactor, Anchusa officinalis suspension culture was cultivated to a cell density of 27.2 g l −1 DW in 14 days at a perfusion rate of 0.123 per day. The maximum total extracellular protein concentration attained 1.11 g l −1. Complete cell retention was achieved throughout the culture during which the maximum packed cell volume (PCV) exceeded 80%. In comparison, the maximum cell density and extracellular protein concentration in the batch culture were 12.6 g l −1 DW and 0.47 g l −1, respectively. SDS-PAGE of the extracellular protein samples revealed two major bands at 58 and 47 kDa, each accounted for approximately 45% of the total secreted proteins.