Fig. 7
Photosynthesis–irradiance (PI) and biomass productivity of a selected strain. a Photosynthesis–irradiance (PI) curves of a selected strain (E2) showing increased photosynthetic activity; data are expressed as the mean ± SD, n = 4. b Evaluation of the biomass productivity of strain E2 in lab-scale fed-batch cultures. Illumination was set to 400 μmol photons m−2 s−1 at pH 8.00. The starting culture concentrations were 150 × 106 cells/ml (corresponding to OD750 = 4.5, a 1 g/L biomass concentration), and these concentrations were re-established every 2 days while the cells were still actively growing. Biomass productivity was calculated as reported in the “Methods” section, and the presented values are the averages obtained from 4 weeks of culture; significant differences from WT are marked with an asterisk (ANOVA, p value <0.05)