Fig. 4

Extracellular uptake and formation rates (unit: mmol g_CDW⁻¹ h⁻¹) of substrates, products, and respiration during parallelized short-term metabolic analysis of E. coli NT1446 pF112aroFBL_Kan producing l-tryptophan. Perturbation was achieved by three-stage feeding profiles containing each glycerol, glucose, pyruvate, and succinate. Respiration rates: oxygen uptake (OUR) and CO₂ production (CPR); biomass specific substrate uptake rates of glycerol (GLYC), glucose (GLUC), pyruvate (PYR) and succinate (SUC) and biomass-specific production rates of l-tryptophan (l-trp) are depicted. Numbers 1–3: metabolic steady-state conditions, resulting from a corresponding three-stage feeding profile. Ref: Extracellular rates in the 15 L fed-batch reference process during metabolic analysis time