Figure 7
From: Pseudomonas aeruginosa β-lactamase induction requires two permeases, AmpG and AmpP
Activity of the ampG and ampP promoters. Promoter activity of the ampG and ampP genes was analyzed using lacZ transcriptional fusions integrated at the att locus of PAO1, PAOampR, PAOampG and PAOampP (see Materials and Methods and text for details). Cells were grown to an OD600 of 0.6 - 0.8, at which time cultures were divided into two and one set treated with 100 μg/ml benzyl-penicillin. After three hours, cells were harvested and β-galactosidase activity assayed as described [10]. All 16 conditions were assayed at the same time but are divided into two panels for visualization purposes. Each value is the mean of at least three independent experiments. The asterisk refers to p-values < 0.05, which were calculated using the two tailed Student's t-test.