Fig 5.

Metabolic fluxes in recombinant E. coli BL21(DE3)(pLysS) strains during exponential growth at 30°C in M9 medium on 5 g liter⁻¹ glucose (4:1 mixture of 1-¹³C-labeled and U-¹³C-labeled glucose) in the absence or presence of 4 mM proline. Rates were normalized to the glucose uptake rate. For external fluxes, the experimental error is reported. The 90% confidence intervals on intracellular fluxes were obtained via Monte Carlo analysis. The error on glutamate and proline demand was estimated from data in the literature on biomass precursor demand. *, the glyoxylate shunt flux was set to 0 in the reported simulations (see File S3 in the supplemental material for experimental details).