Fig. 7

Susceptibility and ROS formation in P. xenovorans pIZoxyR exposed to paraquat. A Susceptibility assays of P. xenovorans strains exposed to paraquat (PQ). Paper disks soaked with paraquat (1–20 mM) were placed on P. xenovorans strain bacterial lawns. Zones of growth inhibition around the disks were recorded after 24 h incubation at 30 °C. The diameter of 6 mm corresponds to the disk diameter and indicates no inhibition. Inhibition zone values were calculated as the mean ± SD of three independent experiments. Letters under the error bars indicate significant differences between strains in each treatment. B ROS quantification assay. P. xenovorans pIZoxyR was grown on glucose (5 mM) until exponential growth phase and exposed to paraquat (20 mM). ROS formation of non-treated cells was also monitored. Fluorescence was monitored after incubation with HPF at 490 nm (excitation) and 515 nm (emission). Fluorescence values were calculated as the mean ± SD of three independent experiments. Letters under the error bars indicate significant differences between strains in each time