| Abstract: | A batch fermentation is modelled with constant and variable yeild terms. It is shown that the model cannot exhibit oscillations if a constant yield term is used. Oscillations in the cell concentration, but not in the limiting substrate concentration, can be simulated if a variable yield function of the limiting substrate is used. Conditions, for which the variable yield needs to satisfy in order to generate oscillations in the cell concentration, are discussed. The primary condition is that the yield must become zero at the same time that the specific growth rate does. Experimental results exhibiting oscillatory behavior are presented and compared with the proposed model. |
