Figure 2

Precultivations of 15 E. coli BL21(DE3) clones and an E. coli BL21(DE3) control without plasmid under non-inducing conditions. Oxygen transfer rate (OTR) as a function of time for: (A) first preculture performed in complex TB medium, and (B) second preculture performed in Wilms-MOPS mineral medium. The arrows indicate the time points the cultures were harvested and used for inoculating the next cultivation step. The dotted line in (B) highlights the depletion of glucose. Cultivation conditions: 37°C, 250 mL flasks, filling volume 10 mL, shaking frequency 350 rpm, and shaking diameter 50 mm.