Cultivation of Insect Cells in Airlift Reactors: Influence of Reactor Configuration and Superficial Gas Velocity

Large-scale cultivation is an essential step towards the feasible production of baculovirus in insect cell cultures. Airlift reactors appear to offer considerable advantages over other insect cell culture systems. In order to evaluate the impact of reactor design on the behavior of insect cell cultures, the IPLB-Sf-21 cell line was cultivated in three different concentric tube airlift reactors that differ in their geometrical parameters. The ratio of downcomer to riser cross sectional areas, the shape of the bottom and the ratio of height to diameter of the reactor proved to be important since them produce significant differences on cell growth behavior. Modifying the reactor design the cellular growth rate could be improved from 0.016/h to 0.031/h, while the maximum viable cell density could be elevated from 9x10 to 2.4x10 cells/ml. Once selected a reactor configuration, the influence of gas flow rate was determined, finding an optimal value of superficial gas velocity that renders sufficient oxygenation without any significant effect on the cellular viability. In addition, the influence of the reactor design on fluid circulation in the reactor was tested.