Fig 5. Effect of OmpR and growth phase on acrR and acrAB promoter activity.

Strains Ye9 and AR4 carrying the promoter-gfp fusion constructs were cultivated in LB medium at 27°C to exponential phase (A) and stationary phase (B). Data represent mean fluorescence activity values normalized to the OD₆₀₀ of the culture (± standard deviation) from three independent experiments performed in triplicate. The significance of differences between the values was calculated using Student’s unpaired t-test (ns [non significant]—p>0.05, *—p<0.05, **—p<0.01).