Stirred bioreactors are still the most widely used bioreactors in biopharmaceutical production. Traditionally, the stirrer is driven via a shaft. However, this always carries the risk of contamination. An alternative is the stirred bioreactor developed here, which is magnetically driven by the Levitronix® BPS-i30 pump drive. This allows a contactless and magnetically driven stirrer which reduces the risk of contamination and provides an enormous rotational speed range.
Typically, a distinction is made in bioreactor design between cell culture and microbial design, as different requirements are to be met by the system in each case. With the help of our developed system, it is possible to achieve similar or better cultivation results compared to commercially available benchtop bioreactors (in terms of cell density and productivity).
In a first step, CFD simulations were performed for the process characterization. This resource-saving procedure allowed various setups to be investigated on the computer and suitable designs can be preselected. In particular, different stirrer designs were investigated. Selected designs were then characterized in the laboratory using standard biochemical engineering characterisation methods (mixing time, power input, oxygen transfer etc.). Following this, the system was biologically evaluated and compared with commercially available bioreactors. CHO cell lines were used on the one hand and an Escherichia Coli strain on the other.