Figure 3
Continuous-feed, mixed carbon medium chemostat culture of E. coli cells. E. coli cells were inoculated into the fermenter at an initial OD ~ = 0.04. The flow rate of the continuous-feed culture was adjusted every 24 hr and samples were collected after the cell density has stabilized. (A) At the indicated dilution rates samples were tested for culture density (OD600nm), pH, cell volume, and cell buoyant density; (B) displays the concentration of the indicated substrates of the mixed carbon growth medium at the indicated dilution rates, together with the concentration of the secreted acetate. In (C) the consumption ratios, which are calculated as the ratio between individual substrate uptake rate and the total carbon uptake rate, are shown at the indicated dilution rates.