Figure 3.

Effects of KCl on swarming motility of wild-type E. coli and strains with mutations in key charged residues. (A) Swarming rates of wild-type and mutant strains in soft-agar plates containing KCl at the concentrations indicated. Data are the average of 10 determinations for the wild type and 2 determinations for each of the mutants. (B) Swarming rates of the charged-residue mutants, measured relative to wild-type controls present on the same plates at various concentrations of KCl (mean ± SD; n = 3).