Table I.

V_max and K_1/2(Ci) of photosynthetic O₂ evolution in fast-induced and noninduced cells of two cyanobacterial species

Kinetic Parameters	High-Ci Cells	Low-Ci Cells	Fast-Induced Cells
			+CA	−CA
PCC7002
Vmax (μmol mg−1 Chl h−1)	535  ± 35	519  ± 45	536  ± 32	534  ± 24
K1/2(Ci) (μm)	161  ± 18	13  ± 2	20  ± 2	167  ± 22
PCC7942
Vmax (μmol mg−1 Chl h−1)	205  ± 20	298  ± 31	218  ± 26	222  ± 17
K1/2(Ci) (μm)	253  ± 28	14  ± 4	24  ± 6	265  ± 22

High- and low-Ci cells of the marine cyanobacterium Synechococcus sp. strain PCC7002 and the freshwater Synechococcus sp. strain PCC7942 were grown continuously on 2% CO₂ or 20 μL of CO₂ L⁻¹, respectively. Fast-induced cells were obtained from high-Ci cells, which were allowed to run out of external Ci for 10 min either in the presence or absence of CA (100 Wilbur-Anderson units mL⁻¹). The data were obtained from experiments similar to those shown in Figure 1 and they represent the mean ± sd from three to four independent experiments.