Fig. 5: Impairing S-nitrosylation status of OxyR, KatG, and GltD affects biofilm-associated phenotypes.

A Biofilms of E. coli WT, oxyR_C25S, katG_C16S, and gltD_C108S mutants, complemented or not with the corresponding plasmid-based allele or empty vector, were grown in continuous-flow microfermenters for 24 h in LB medium before quantifying the biofilm biomass. The level of biofilm formed by the WT strain was set to 100%. B Sensitivity to H₂O₂ oxidative stress of an oxyR_C25S mutant compared to the WT and ∆oxyR mutant. The distance of growth inhibition from the edge of the disk to the edge of the growth zone was measured and was set to 100% for the WT strain. C Increased sensitivity to oxidative stress of katG_C16S mutant. The sensitivities to H₂O₂ of E. coli WT and katG_C16S mutant complemented with corresponding plasmid-based allele or empty vector were compared. The distance from the edge of the disk to the edge of the growth zone was measured and was set to 100% for the WT strain. D S-nitrosylation-dependent decreased motility of gltD_C108S mutant. The motility of E. coli WT and gltD_C108S mutant were compared in aerobic conditions and in anaerobic conditions in presence of KNO₃. Assays were performed on 0.3% agar plates and incubated overnight at 30 °C. All experiments were performed in triplicate, mean values are reported and error bars represent standard deviations. **p ≤ 0.05, ***p ≤ 0.01. See also Figs. S2, S5 and S6.