classified as structured/unstructured or segregated/non-segregated. Cell models
considering the existence of intracellular components are termed structured otherwise
they are termed unstructured. They may also assume the existence of a morphological
structure, being then termed segregated models, or may assume that all cells are identical
(only one morphological form) being then termed non-segregated models.
For bioprocess optimisation, control and supervision, unstructured and non-segregated
models are the ones which have been applied in the past obviously for the sake of
simplicity. The other side of the coin is that unstructured and non-segregated cell models
are rough simplifications of the reality. As such parametric uncertainty is one of the
frequently mentioned problems affecting robustness of underlying model-based closed-
loop control and optimisation.
In developing unstructured and non-segregated cell models, principles of macroscopic
stoichiometry and Monod-type kinetics (Table 3.1) are employed. The starting point of
such an analysis is the establishment of a set of biochemical equations describing the
most
Table 3.1 Monod type kinetic models
according to Monod:
according to Blackman:
according to Moser:
according to Contois:
according to Teissier:
according to Kargi & Shuler:
according to the logistic formula:
analogous to non-competitive inhibition (formally: qmax
is affected)
analogous to competitive inhibition (formally: Ks is
affected)
analogous to un-competitive inhibition (formally: both
qmax and Ks are affected)
New methodologies for multiphase bioreactors 3 69