Fig. 5
From: Electrode-assisted acetoin production in a metabolically engineered Escherichia coli strain
Results of the unbalanced fermentation approach. a Chemical analysis of the chronoamperometric experiment. The glucose concentration decreased by 12.4 ± 0.9 mM over 90 h. The acetoin concentration increased to 9.8 ± 0.2 mM after 90 h. b Chronoamperometric detection. The current density decreased from its maximum value of 25.7 µA/cm2 at the beginning and then stabilized after roughly 30 h around a value of 6 µA/cm2. c Chemical analysis of the open-circuit potentiometry experiment. No significant decrease in glucose was detected while a small amount of acetoin was formed (1.2 ± 0.03 mM). d Open-circuit potentiometry. The cell potential decreases in two steps from −200 to −380 mV