Fig. 1

Growth and isobutanol titer produced from engineered Synechocystis PCC 6803 strain pEEK2-ST in different cultivation conditions. a Growth and isobutanol production titer of the cells grew under 15 μmol photons m⁻² s⁻¹, 50 μmol photons m⁻² s⁻¹, and 100 μmol photons m⁻² s⁻¹ light intensities without any pH adjustment. b Growth and isobutanol production titer of the cells grew under 50 μmol photons m⁻² s⁻¹ with different pH adjustments. The target pH range for the pH adjustment, using either HEPES or HCl, was between pH 7 and 8. The pH labeled on the growth curve was the final pH measured in the end of the cultivation. Results represent the mean of three biological replicates; error bars represent standard deviation