Fig. 8

The effect of hydrogen peroxide on stationary phase lrgAB induction and growth. A-C: The PlrgA-gfp reporter strain was grown in a low-glucose (11 mM) FMC medium supplemented by 0 (a), 0.002 (b) and 0.004% (c) hydrogen peroxide (H₂O₂). D-F: The PlrgA-gfp reporter strain was grown in the same FMC medium supplemented by 0 (d), 0.002 (e) and 0.004% (f) hydrogen peroxide (H₂O₂), as well as 1 mM pyruvate (pyr). G-H: The PlrgA-gfp reporter strain was co-cultivated with S. gordonii DL1 (Sg) in the same FMC medium without pyruvate (g) and with 1 mM pyruvate (H). Relative gfp expression (green square) and OD₆₀₀ (grey circle; OD) were monitored on a plate reader (see Materials and Methods for details). The results are representative of two independent experiments