Figure 1

Example of cell growth and changes in the Chlorophyll to Phycocyanin ratio in photobioreactor cultivation experiments. The figure shows the (a) cell growth and (b) absorption spectrum for induced ethanol producer and wt cells of PCC6803 and the (c) cell growth and (d) absorption spectrum for induced ethanol producer and wt cells of PCC7002. For both strains the wild type is compared to ethanol producing strains. Due to changes in the carbon partitioning upon ethanol production the induced culture exhibited less cell growth compared to the repressed culture. In addition the amount of phycocyanin (620 nm) was down-regulated in the ethanol producer compared to the non-producing culture which showed a typical wt pigmentation phenotype.