FIG. 2.

Biofilm formation by mutants with altered swarming motility. Mutants were sorted on the basis of increasing swarming motility. Bacteria were incubated in adjusted BM2 medium in polystyrene microtiter plates for 20 h at 37°C, and biofilms were stained with crystal violet. The data are representative of three independent experiments with eight replicates for each mutant and are expressed as the fold change in the optical density at 595 nm (OD 595nm) of the mutant compared to the wild-type. Asterisks indicate mutants that showed a statistically significant change in biofilm production (P ≤ 0.05, Student's t test). WT, wild type.