Fig. 7

Performance of the engineered promoters at two different temperatures: a 37 °C and b 25 °C. The fluorescence of E. coli strains expressing mCherry under the native promoter P_emrR and the engineered promoters P_vtac, P_vtrc, and P_vtic were monitored after 8 and 24 h of induction at 37 and 25 °C, respectively, using a fluorescence plate reader and normalized based on the cell density—OD₆₀₀. The cells were grown in an M9 salt medium containing 25 mg l⁻¹ chloramphenicol, 20 g l⁻¹ glucose and 5 g l⁻¹ yeast extract at the corresponding temperatures and a 3 mm shaking amplitude. P_emrR, red squares; P_vtac, orange triangles; P_vtrc, grey circles; P_vtic, blue diamonds. Each data represent the average of three biological replicates and the error bars represent s.d. The standard deviations between the biological replicates were too small for the error bars to be visible