This was demonstrated experimentally [14]. The course of the selleck inhibitor metabolites and the enzymes are shown in Figure 6. Based on the model structure and the estimated parameters, all enzymes and metabolites show an increasing behavior while PEP is nearly constant over the growth rate. Figure 6 Left (plot A): Course of the enzymes PfkA (solid), lumped glycolysis

(dashed), and Pyk (dash-dotted) with the growth rate. Right (plot B): Course of the metabolites glucose-6-phosphate (solid), fructose-1,6-bisphosphate (dashed), PEP (dash-dotted), and … 2.4. Dynamic Model Having the model parameters for the uptake Inhibitors,research,lifescience,medical systems available, the complete system including PtsG induction kinetics (see Appendix) was simulated with fine-tuned parameters (empirical tuning of the parameters). First, time course data with

simulated Inhibitors,research,lifescience,medical and experimental data are shown in Figure 7 for selected values of IPTG. Figure 7 Dynamic model simulation and comparison with experimental data. A: optical density, B: glucose in g/l, C: PtsG in arbitrary units, D: degree of phosphorylated EIIA (dimensionless). Left: IPTG 0 μM; Right IPTG 140 μM. Shown are data for optical density (plot A), extracellular glucose concentration (plot B), PtsG (plot C), and EIIA phosphorylated (plot D) for no IPTG (left) and maximal IPTG concentration (right). The calculation of the optical density in plot A shows a very good agreement with the experimental data; glucose uptake for Inhibitors,research,lifescience,medical high concentrations of IPTG could not be reproduced accurately as the yield coefficients for each experiment were different and in the calculations, a mean value was used. Furthermore, Inhibitors,research,lifescience,medical the fit of the parameters for glucose uptake (Figure 5) also shows differences between simulated and experimental values that can be seen here again. For a high value of IPTG, the

value of PtsG measured in the exponential phase could be described as well as the degree of phosphorylation of EIIA. Steady state values (taken in the exponential phase) are considered and compared with simulation results (Figure Inhibitors,research,lifescience,medical 8). Plot A shows simulation results for growth on non-PTS (upper curve) and PTS (lower curve) carbohydrates. For small uptake rates, both curves converge. For large others growth rates, the PTS reaches its capacity limit since the energy for the transport is generated in the glyoclysis itself. Figure 8 Left (plot A): Degree of phosphorylation of EIIA versus growth rate. Shown are simulation results for growth on non-PTS carbohydrates (upper solid line) and for growth on PTS carbohydrates (lower solid line). Values for the experiments 1–7 are … For increasing values of IPTG, the system moves from one curve to the other, indicating a change of the uptake system based on the induction of PtsG: the degree of phosphorylation decreases while the growth rate increases. A comparison of the experimental data with the simulation data reveals differences in the growth rate.