Light-saturation curves of photosynthesis. Curves were obtained with the C. sorokiniana wild-type and the TAM-2 (a) and TAM-4 (b) mutants. The light-saturated Pmax was 1.5-fold higher in the TAM-2 mutant than in the wild type, suggesting a greater productivity on a per-Chl basis. In the TAM-4 mutant, the light-saturated O2 yield was not significantly higher than that for the wild type. Data are expressed as mean ± SD, n =4.