2. VALIDOGEN's bioreactor cultivation process optimization workflows supported by microbioreactors
In addition to the benefits for VALIDOGEN`s Pichia strain development procedures, microbioreactors represent an appealing alternative to larger lab-scale bioreactors for cultivation process development including Design of Experiment (DoE) programs. While results are conclusive for bioreactors, the small reactor volumes and shortened cultivation time as well as the fact that a number of process parameters (such as temperature, pH and feed) can be efficiently controlled, render microbioreactors a powerful cultivation process development tool. This facilitates simultaneous cultivations with a variety of experimental conditions to be carried out in a time- and resource saving manner.
Case study demonstrating the integration of microbioreactors in bioreactor cultivation process development
In order to demonstrate the usefulness of microbioreactors in bioreactor cultivation process development, we performed a DoE based study with a Pichia pastoris strain producing a bivalent VHH. We performed a full factorial design comprising 16 microbioreactor runs (4 factors, 2 levels), each run was carried out in duplicate.
Results and confirmation in lab-scale bioreactors
- amount of N-source
- pH value
- feed composition
- feed rate
As a result of this study several parameter sets yielding enhanced productivity were found and interactions between factors depending on their respective levels were elucidated.
Lab-scale bioreactor cultivations applying these optimized conditions confirmed the findings from the microbioreactor DoE. With the time- and resource-saving application of microbioreactors in this study, a ~40% improvement in VHH yield in comparison to standard conditions was achieved, clearly demonstrating the usefulness of microbioreactors for bioreactor cultivation process development as well as the sound transferability of results from microbioreactors into lab-scale bioreactor.