FIGURE 5.

Surfing motility of PA14 was modestly reduced in mutants with ntrB deleted. (A) Surfing motility was reduced in PA14 mutant strains ΔntrB and ΔntrBC compared to WT. Surfing motility in PA14 mutant strains transformed with plasmid containing ntrB, ntrC, or ntrBC genes was similar to WT transformed with plasmid. Surf plates supplemented with 0.4% mucin were inoculated with 5 μl of planktonic cells suspended at an OD₆₀₀ = 0.4–0.6 in MSCFM, then incubated for 18–24 h at 37°C. Images captured using a BioRad ChemiDoc. (B) Raw surface area coverage (%) of surfing colonies was assessed using ImageJ software. Data reported as mean ± standard error of the mean (SEM) from three independent experiments containing three biological replicates each (n = 9). *P < 0.05, **P < 0.01 according to Kruskal-Wallis nonparametric test followed by Dunn’s post hoc analysis.