Fig. 2. Carbon uptake kinetics of Microcystis PCC 7806 acclimated to either low or high pCO₂.

(A and B) Net CO₂ uptake rate as function of the dissolved CO₂ concentration, after acclimation to (A) low pCO₂ and (B) high pCO₂. (C and D) Bicarbonate uptake rate as function of the bicarbonate concentration, after acclimation to (C) low pCO₂ and (D) high pCO₂. Carbon uptake kinetics were measured after ~20 days of acclimation to the steady-state conditions in the chemostats. Measurements were replicated fourfold at low pCO₂ and threefold at high pCO₂, as indicated by the different colors. Lines are Michaelis-Menten fits to each of the replicates (see table S2 for parameter estimates). Insets zoom in at the carbon uptake kinetics at low dissolved CO₂ and bicarbonate concentrations.