Figure 1
Physiological impact of reduced phosphate supply in chemostat cultivations. A. Schematic set-up of the Pi wash-out experiment. The gradual decrease of the feed supply rate (pump P1) was compensated by a gradual increase of the feed rate of a medium lacking any phosphate source (DMM-P, pump P2). The overall dilution rate was thus kept constant, and the residual phosphate in the culture was washed out. B. An overview on the impact of decreasing phosphate supply during the wash-out process. The insulin titers (IAP, blue circles) increased when the phosphate supply was restricted (pump A, red dashed line). C. representation of the biomass yield (black, 0.13-0.43 g/g), IAP productivity (blue, 0.196-0.392 mg/gh), glycerol yield (green, 0-0.615 mmol/mol), and ethanol yield (red, 0-12.68 mmol/mol), as a function of the supplied phosphate level in individual cultures. All four parameters were normalized to a range of zero (min. values) to one (max. values). D. radar plot representation of the biomass yield (green) and the corresponding IAP yield (blue).