An evaluation of transfer function models for the transient growth response of microbial cultures

Abstract

Experiments were conducted to evaluate the ability of transfer function models to characterize the transient-state growth response of Pseudomonas putida grown in l-lysine minimal media. The results indicated that, while transfer function models could be used to characterize individual transient responses, the values of the parameters in the models varied with the pre-transient growth conditions (i.e. the steady-state specific growth rate prior to the transient) and the type of transient (shift-up or shift-down). Thus, the models were not very useful for predicting transient responses. It is suggested that this poor predictive power is the result of a complex physiological adaptation which is not adequately accounted for in simple transfer function models.