Growth curve under different light intensities and CO
concentrations. (a) Growth curve under 0.04% CO2; (b), 1% CO2; (c), 2% CO2; and (d), 4% CO2. Light intensities are 50 (circles), 300 (squares), and 600 μmol photons m−2 s−1 (diamonds). Error bars indicate standard deviations (SD) of three replicated experiments. In some data points, error bars obtained by three replications are smaller than symbols.