FIG 4.
Effect of 14-Me-C16:Δ2 on the AHL QS system in B. cenocepacia H111. (A) Effects of 14-Me-C16:Δ2 on cepI gene expression were measured by assessing β-galactosidase activity of the cepI-lacZ transcriptional fusions. B. cenocepacia H111 was grown in the presence or absence of 14-Me-C16:Δ2 (100 μM). Samples were taken from each culture at the OD600 values for the indicated time intervals. (B) Quantitative analysis of AHL production in B. cenocepacia H111 in the presence or absence of 100 μM 14-Me-C16:Δ2 at different time points. For convenient comparison, AHL production of the WT at 10 h was arbitrarily defined as 100% and used to normalize the signal ratios of the different time points. The results are based on three independent experiments. Error bars represent the means ± SD. Significant differences (*, P < 0.05; **, P < 0.01; ***, P < 0.001) between the tested compound and its control (n = 3) are shown.