Fig. 4

In vivo ADP-specific sensor based fluorescence assay. A The recombinant strains of PCC 6803 (SSL142) were grown with atmospheric CO₂ and induced in BG-11 + 50 µg/mL of kanamycin were subjected to the fluorometric assay with different pH (3, 4, 5 or 6) citrate buffers. Their comparative analysis over 150 min indicated a significant increase in the fluorescence at pH 4 followed by 3, 5 and 6. B SSL142 was grown in BG-11 + 50 µg/mL of kanamycin, with and without 20 mM of NaHCO₃. Both the cultures were subjected to the fluorescence assay at pH 4. Fluorescence values were normalized with the corresponding OD₇₃₀, where the results indicated three-fold higher rate of increase in the fluorescence with SSL142 grown in presence of NaHCO₃. All the assays were performed in biological triplicates