Predicted vs. measured metabolic fluxes in the E. coli central metabolism. Comparisons between the FBAwMC-predicted- (orange plots) and measured (blue plots) fluxes as a function of growth/dilution rates for selected reactions in the central carbon metabolism of E. coli. The experimental flux measurements were performed at dilution rates 0.1, 0.25, 0.4, 0.55 and 0.72 h-1. Selected reactions of glycolysis (red boxes), the first reaction of the pentose phosphate pathway (zwf) (magenta box), the TCA cycle (blue boxes), acetate excretion pathway (green boxes) and the reactions catalyzed by ppc and aceE connecting the glycolytic- and TCA pathways (yellow boxes) are shown. The solid black circles represent the denoted metabolites while the black arrows represent metabolic reactions labeled by the genes encoding the enzymes catalyzing the respective reactions (see Table S1 in Additional file 4 for the list of abbreviations and information on enzymes encoded by listed genes). The error bars for predicted fluxes indicate the standard deviation over 1,000 choices of the crowding coefficients among the list of values estimated for ~100 E. coli enzymes, whereas the error bars for the experimental fluxes represent the standard deviations for three independent measurements.