High density cultivation of plant cells in a new aeration-agitation type fermentor, maxblend fermentor®

Abstract

The applicability of a new aeration-agitation type fermentor with a grid-paddle type impeller and a spiral-sparger, Maxblend Fermentor® (MBF) for high density cultivation of plant cells, was investigated. The MBF showed a high capacity for oxygen supply and extremely low hydrodynamic stress in aeration and mixing compared with a conventional fermentor (CF). When Oryza sativa cells were cultivated at a k L a of 20 h −1, a high cell density cultivation of about 30 g dry cell weight per liter was accomplished in both fermentors and there were few differences in culture performance between the two. On the contrary, considerable differences were observed when Catharanthus roseus cells, which seemed to be sensitive to physical stress, were cultivated at a k L a of 20 h −1 in both fermentors. The MBF exhibited excellent cell growth characteristics, achieving about 19 g dry cell weight per liter, because of its superior oxygen supply and low hydrodynamic stress in aeration and mixing in highly viscous cultures containing high density cells. In CF only about 9.5 g dry cell weight per liter was achieved because of its high hydrodynamic stress.