**Figure 2** Squalene concentrations [mg l-1 OD750-1] in response to gene overexpressions. Values are represented as the means of three biological replicates, standard deviations are shown. 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 by inserting an additional copy of the specified gene under the control of the rhamnose-inducible promoter Prha into its genome. Asterisks ( * ) represent the p-value of the two-sided t-test between the respective strain and the control strain at the same rhamnose concentration (* denotes a value of p<0.05, ** denotes p<0.01 and *** denotes p<0.001). Samples were measured after three days of incubation with the specified concentration of rhamnose as an inducer.
