Fig. 1

Accumulation of reactive oxygen species (ROS) in P. putida mt-2 following matric stress. Matric stress was simulated by incubation in liquid culture media amended with PEG-8000 to obtain matric potentials of −0.5 MPa or −1.5 MPa. ROS were detected as oxidation-dependent green fluorescence of the ROS-sensitive probe 2′,7′-dichlorodihydrofluorescein diacetate. a Histogram illustrating the fluorescence from one representative experiment where cells were either incubated without PEG-8000 (considered control, Ctrl) or exposed to PEG-8000 (−1.5 MPa). b Average fluorescence intensity of cells from PEG-8000 treated cultures and Ctrl cultures. Data represent mean values ± S.D. (n = 3)