Foaming behaviour is complex to model and in some cases unpredictable. Finding the right balance between aeration and agitation while the fermentation is proceeding without interruption is a challenge.
Extensive foaming interrupts the process and leads to yield loss or loss of the complete fermenter. Dosing anti-foam to the fermenter can keep foaming under control.
Anti-foaming agents are however known to potentially inhibit growth and can affect DSP by, for example, blocking membrane filters or negatively influencing product crystallization. Depending on the final application, the choice of antifoam can give rise to issues with final product registration.
Careful selection of a suitable antifoam type and determination of the maximum amount of antifoam that can be added without hampering DSP needs to be determined on lab or pilot scale.