Fig. 5

Cyanophycin accumulation in Synechocystis sp. PCC 6803 wild-type (white bars) and strain BW86 (gray bars) cultivated a with nitrate, b with ammonium, c under phosphate starvation, and d under potassium starvation. A ⁱ–D ⁱ Growth curve of Synechocystis sp. PCC 6803 (WT) (circles) and strain BW86 (squares). Y -axes in log 10 shows the OD₇₅₀. Cells of each strain exponentially growing in BG-11 medium were inoculated into 800 ml of the respective BG-11 medium and incubated with an influx of 2 % CO₂ in air. For phosphate starvation, washed cells were grown in phosphate-free medium and were diluted with fresh phosphate-free medium after 2 days of cultivation; this time point was day 2. For potassium starvation, the cells of the inoculum were washed and inoculated into potassium-free medium. In c and d, the nitrogen source was nitrate. Cyanophycin was quantified every second day; the concentration is plotted against the cell dry mass (CDM). Note the different scales on the y-axes