Structural identifiability of the yield parameters in nonlinear compartmental models for bioprocesses

The parameter identifiability of nonlinear state-space models used for the description of biotechnological processes is considered. The identification problem of bioprocesses in a stirred tank reactor essentially concerns the determination of the yield coefficients and reaction rates involved in a general state-space model. Identification of the yield coefficients is the topic of this study. It is shown that the yield coefficient identification can be completely decoupled from that of the reaction rates by means of an appropriate transformation of the dynamical model. The identifiability of the yield coefficients is investigated. It is shown that the identifiability properties of these coefficients can be drawn from the structure of the underlying reaction scheme. Necessary and sufficient identifiability conditions are given in the form of some simple algebraic tests