FIG 7 .

Activation of expression from the btaI3 promoter by AHLs. (A) The luciferase activity of the chromosomal btaI3-lux transcriptional fusion was monitored at (B) various times during growth in cultures of the B. thailandensis E264 ΔbtaI1 ΔbtaI2 ΔbtaI3 mutant strain. Cultures were supplemented with 10 µM C₈-HSL, 3OHC₁₀-HSL, or 3OHC₈-HSL. Acetonitrile only was added to the controls. The error bars represent the standard deviations of the averages for three replicates. The luminescence is expressed in relative light units per optical density of the culture (RLU/OD₆₀₀). ***, P < 0.001; **, P < 0.01; *, P < 0.05; ns, nonsignificant.