Although single-use disposable bioreactors are increasingly being introduced in biopharmaceutical production, multiple-use bioreactors made of glass and/or stainless steel are still of major importance. Most benchtop-scale bioreactors, which are almost exclusively fabricated from glass, are agitated by stirrers because of the wide range of applications and comprehensive knowledge about fluid flow, power input, mixing, mass transfer, and shear stress. They are used for screening experiments, in the seed train, or as scale-down models for larger vessels.
The HyPerforma Glass Bioreactor, which has a bench-top-scale vessel with a maximum working volume of 2.0 L, was designed to be suitable for cell culture applications, and is agitated by a combination of an axially down-pumping segment blade impeller and a bottom-mounted, radially pumping, modified Rushton turbine.
The HyPerforma Glass Bioreactor can be controlled using the Thermo Scientific™ HyPerforma™ G3Lab™ Controller in conjunction with Thermo Scientific™ TruBio™ software powered by the Emerson™ DeltaV™ system (Figure 1).
The present study focuses on the cultivation of Sf9 insect cells producing the SEAP, with the baculovirus expression vector system. After expanding the cells in batch mode for two days using serum-free medium without components of animal origin, the cells were infected by the baculovirus with defined infection characteristics. The bioreactor cultivation ran up to eight days, achieving a maximum viable cell density of 4.964 x 106 cells/mL. The maximum SEAP activity was 56.4 U/mL. By increasing impeller speed and sparging of oxygen it was possible to maintain the dissolved oxygen (DO), level around the set point of 50% saturation, while preventing excessive shear stress or foam production due to aeration.