Foaming and its Control in Bioprocesses

Abstract

Control of foaming in bioprocesses presents a dilemna, since a highly surface active heterogeneous system has to be adequately aerated and agitated while the bioreaction is proceeding without interruption. This paper deals with mechanisms of foam formation and destruction, causes and effects of foaming in bioprocesses and different methods of foam destruction and prevension. Special emphasis is given to chemical anti foaming agents and to the determination of their efficiencies. Important criteria for the choice of a suitable anti foaming agent are discussed. It is concluded that foam suppression or collapse is a result of a fine balance between the effects of var ious surface active agents. Therefore, in choosing and employing an anti foaming agent, the aim, foam suppression or collapse, should be well defined and the interactions between biomedia and the anti foaming agent should be experimentally determined. Finally, a few suggestions for future research are mentioned.