Figure 9.
Effect of light on cellular growth requirements for (A) iron and (B) manganese in the coastal diatom Thalassiosira pseudonana at 20°C. (A) Relationships between specific growth rate and Fe:C molar ratio for cells growing under a 14:10 h light:dark cycle at light intensities of 500 (black triangles), 85 (green triangles), and 50 (blue triangles) μmol photons m−2 s−1. Open diamonds give data for cells growing at the highest light intensity (500 μmol photons m−2 s−1) but a 50% shorter daily photoperiod (7 h). (B) Relationships between specific growth rate and cellular Mn:C molar ratio for cell growing under a 14:10 h light:dark cycle at light intensities of 500 (black circles), 160 (red circles), and 90 (green circles) μmol photons m−2 s−1.