Figure 3
From: Norvaline is accumulated after a down-shift of oxygen in Escherichia coli W3110
High cell density cultures of E. coli W3110 without (A, C) and with a stirrer downshift resulting in oxygen limited culture (B, D). The graphs show the data for cell dry weight (g L-1), dissolved oxygen tension (DOT), glucose concentration (A, B) and the anaerobic metabolites acetate, lactate, formate, ethanol, succinate (C, D, symbols shown in C). Anaerobic conditions in graphs (B, D) were caused by a downshift of the stirrer speed whereas the aeration rate was kept constant, as described in the Material and Methods section. The glucose feed was started at 0 hours. The stirrer downshift was performed at -10 min.