Fig. 4

Simulations of Escherichia coli growing with different combinations of lactose and D-glucose. Simulations were performed using the genome-scale metabolic model of E. coli K-12 MG1655 [37] and the reconstructed regulatory network of the lac operon. Are shown here the initial concentrations of the two carbon sources, the calculated steady-state (attractor of size one) qualitative value for some of the components of the regulatory network, and the value of the objective function (growth rate). Lower graph legend : FBA: Simulation performed using FBA without considering the regulatory network; RSA + FBA: Simulation performed using RSA and FBA; experimental data: values extracted from [36]. Regulatory network legend: E: EIIA component of the D-glucose PTS transporter; P: lactose permease; B: Beta-galactosidase; I: lac I regulator