**Figure 4** Whole cell spectra of selected strains. Spectra were measured after three days incubation with 5 mM rhamnose in 1 cm cuvettes after equalizing the OD750 across all strains and subtracting the OD750 as a baseline correction. WT represents the *Synechocystis* sp. PCC 6803 wild type, while the control strain is *Synechocystis* sp. PCC 6803 Δshc pSHDY rhaS, from which the overexpression strains were constructed. The visually blue phenotype of the sqs overexpression strain in the cuvette is pictured in the bottom left.
