Fig. 1

Extended batch cultivation of U. cynodontis Δfuz7^r Δcyp3^r p_etefmtta p_ria1ria1 in a 2-L fermenter with 100 g/L initial glucose and sequentially decreasing glucose feed rates. Depicted are A oxygen transfer rate (OTR) and concentrations of glucose and itaconic acid, B volumetric aeration rate and filling volume, C pH, optical density (OD₆₀₀), cell dry weight (CDW) and volume of titrated base solution and D respiratory quotient (line at RQ = 1) and erythritol concentration over time. Cultivation was performed at T = 30 ℃, n = 300–800 rpm, pH_initial = 5.92, pH_control = 3.6 (10 M NaOH), OD_600,initial = 0.5 and V_L,initial = 1250 mL in adapted Verduyn medium in a 2-L fermenter. Aeration rate adjusted at beginning of each feed phase to reach a mean volumetric aeration rate of q_in = 60 SL/L/h. Glucose was fed from a 517.3 g/L solution, resulting in feed rates of I: 3.6 g/h, II: 3.0 g/h, III: 2.4 g/h, IV: 1.9 g/h and V: 1.3 g/h. Feed rates were calculated from glucose accumulation in the experiment shown in Fig. SI 7. For concentrations, mean values of two replicates are shown