Three-phase oxygen absorption and its effect on fermentation

The absorption rate of oxygen in the presence of a second, dispersed, organic phase can be significantly increased due to the higher solubility and diffusivity of oxygen in the organic phase. The oxygen supply of micro-organisms, which is very often a limiting factor during fermentation, can be improved, and the critical level of oxygen in the fermentation broth can be avoided by using dispersed organic phase. This paper reviews the models of the enhanced absorption rates and their integration into mass balance equations of fermentation. Several calculations were carried out to illustrate the effect of the dispersed organic phase and kinetic parameters on the absorption rates and on fermentation with double-substrate-limitation kinetics applying batch and continuous operation modes. Using software taking from the literature, the effect of the organic phase on the baker's yeast production is also presented in fed-batch mode.