FIG 5.

CysE is required for swarming but not swimming motility of S. marcescens in rich medium. (A) Suspensions (10 μl) of bacteria were spotted on LB medium containing 0.6% agar and incubated at 30°C for 16 h to facilitate swarming motility. Images of swarm growth in 100-mm petri dishes were captured from a top-down perspective. (B) Bacterial swarming was quantified by measuring the diameter (mm) of growth for each strain. Bars represent the mean (±standard deviations) swarm diameters from three independent experiments, and asterisks identify swarm diameters that were significantly less than those of the wild-type (WT) or complemented cysE mutant (cysE⁺) strains as indicated (t test, P < 0.01). (C) Swimming capability of S. marcescens strains was determined as described for panels A and B with the exception that bacteria were cultured on LB medium containing 0.25% agar for 8 h.