Fig. 1.

Slow fluorescence kinetics of intact cells of T. pseudonana during dark incubation. Cells (Chl a content of 2 μg ml⁻¹) were harvested from the growth light conditions and used immediately. The oxygen concentration of the medium is depicted by the shaded area. Before the start of measurements, samples were bubbled with nitrogen to reduce the initial oxygen concentration to approximately 20% of oxygen-saturated water. Oxygen was completely removed from the medium after 60–70 min and reintroduced after 125 min of dark incubation.