Figure 2.
A, Photosynthetic depletion of Ci in the cuvette of the mass spectrometer by Synechocystis PCC6803 cells exposed to CO2-free air for 15, 60, 120, 180, and 300 min. Other conditions were as detailed in “Materials and Methods.” The cell suspensions were re-illuminated (↓) and allowed to deplete the Ci in the medium until near the CO2-compensation point. A representative set of traces for three independent experiments is shown. B, Rates of Ci uptake below 70 μm calculated from the Ci drawdown traces plotted in A by estimating the dCi/dt at the indicated external Ci levels.