Effect of fermentation defoaming agents on TFF
Tangential flow filtration (TFF), also known as cross flow filtration (CFF), comprises a rising technology in the last decades for the dewatering, isolation, and concentration of products of interest (e.g. biomolecules, metabolites and cells) from bioprocesses. Tangential Flow fitlration consists on the passage of the product feed in parallel to the surface of the filtering element/membrane . The most bioprocesses use surface-active agents to reduce the foam formation, widely known as antifoams, defoamers and defoaming agents among others.
These defoaming agents can be of different kinds depending on what they are made of, being silicone antifoams, oil antifoams, and glycol antifoams common examples of them. Usually, the main criteria for the selection of the right antifoam are effectiveness in low amount, biocompatibility and price. Nevertheless, the criteria selection also must take into account the downstream process type to be used, in order to avoid fouling problems and the formation of sub-layers of particles. This would otherwise reduce the filtration yields, having a detrimental impact on the flux (i.e. operation times), the operating costs of production, the cleaning, the maintenance and the optimal design of the filtration unit .