Fig. 3.

Bicarbonate uptake. Striped columns denote subsamples from cultures grown in the dark, incubated with H¹⁴CO₃⁻ in the light (dark-to-light) or dark (dark-to-dark). Solid columns indicate subsamples from cultures grown in the light, incubated with H¹⁴CO₃⁻ in the light (light-to-light) or dark (light-to-dark). (Inset) Growth of cultures in the dark (filled circles) and in the light (open circles) from where subsamples for bicarbonate uptake assays were collected at 50 h; the x axis shows time (hours) and the y axis, optical density. Error bars denote SD for duplicates.