Fig. 5
Proof of concept cultivation of U. cynodontis Δfuz7r Δcyp3r petefmtta pria1ria1 in a 2 L fermenter with 100 g/L initial glucose, sequentially decreasing glucose feed rates and in situ separation of itaconic acid by adsorption. Depicted are A oxygen transfer rate (OTR) and concentrations of glucose, itaconic acid and ethanol over time. B, C Are enlarged representations of concentrations of itaconic acid during adsorption cycles over time. Cultivation was performed at T = 30 ℃, n = 300–600 rpm, qin = 60 SL/L/h, pHinitial = 5.75, pHcontrol = 3.6 (10 M NaOH), OD600,initial = 0.5 and VL,initial = 1250 mL in adapted Verduyn medium in a 2-L fermenter. DOT was controlled at 30% by adjusting stirrer speed. Glucose was fed from a 500.3 g/L solution, resulting in feed rates of I: 4.0 g/h, II: 3.3 g/h, III: 2.6 g/h, IV: 1.9 g/h and V: 1.2 g/h. Column was filled with 11.3 mL of Blücher 100562 activated carbon. The adsorption steps of product separation cycles were performed from 47.7 to 48.1 h and 70.6 to 70.9 h. For concentrations, mean values of two replicates are shown