1. Make Sure Your Cells Can Breathe.
Many bioprocesses are aerobic, meaning they use organisms that are dependent on oxygen for metabolic activity and growth. Thus, when scaling up your aerobic cultures from shake flasks to significantly higher volumes in bioreactors, enabling a sufficient oxygen supply is important and at the same time challenging.
In shake flask experiments, shaking increases the exposure of the medium to oxygen in the surrounding air, easily providing a sufficient level of dissolved oxygen. In stirred bioreactors, air or pure oxygen must be introduced to the culture, usually from compressed air cylinders. Spargers distribute the gas more evenly throughout the culture, allowing a higher gas/medium interface for a higher oxygen concentration in the medium.