Figure 6

Activity of the ampC promoter. Promoter activity of the ampC gene 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]. Each value is the mean of at least three independent experiments.