FIGURE 8.

Responses of P. putida FNR proteins to nitric oxide and oxidative stress in vivo. P. putida strains capable of expressing only anr from the chromosome (ANR) or only PP_3233 from a multicopy plasmid (PP_3233⁺⁺) or only PP_3287 from a plasmid (PP_3287⁺⁺) were transformed with the FF-41.5-lacZ reporter plasmid pGS810. Cultures were grown at 30 °C for 3 h under anaerobic (50 ml of anaerobic minimal medium 154 supplemented with 0.4% (w/v) yeast extract and 30 mm l-arginine in a sealed 50-ml conical flask) or aerobic (10 ml of L-broth in a 50-ml conical flask, 200 rpm shaking) conditions in the presence and absence of NOC-7 (20 μm) or paraquat (PQ; 200 μm) as indicated. Samples were taken for measurement of β-galactosidase activity as a proxy for FNR protein activity: ANR (A), PP_3233⁺⁺ (B), and PP_3287⁺⁺ (C). The error bars are the standard deviation from the mean values (n = 3).). p values were determined by Student's t test. **, p < 0.01; *, p < 0.1; NS, p > 0.5.