The generation of foam is common in aerobic bioreactor systems. Foaming can cause a range of problems, including increased contamination risks through potential exhaust filter fouling, poor mass transfer, product/cell entrainment, increased shearing from bursting bubbles, and cell death [1,2,3]. Proper foam control in bioreactors is essential to ensuring a successful culture campaign. The Thermo Scientific™ single-use foam probe is a composite product-contacting probe that has been designed to detect foam in large-scale Thermo Scientific™ HyPerforma™ Single-Use Bioreactor (S.U.B.) operations. Coupled with proper controller integration, the probe has been shown to effectively control foam, even under high-gassing conditions. This capability allows the end user to shift from a time-depended antifoam delivery protocol developed based on educated guesses to a controlled protocol based on an output signal, resulting in less antifoam consumption and providing traceability of foam generation within the bioprocess.
This application note outlines the cause of foam, use of antifoaming agents to control foam, design and integration of the single-use foam probe (including a mounting system and bioreactor controller integration), and several successful case studies utilizing the foam probe in aggressive bioreactor cultures. This study demonstrates that foam can be controlled across all S.U.B. sizes, 50 to 2,000 L.