FIG. 1.

Biofilm assays performed with B. cenocepacia K56-2 (wild type [WT]) and DFA21 (the atsR::pDA27 mutant) containing the control plasmid pDA12 or pAtsR, as indicated in parentheses. Biofilms were quantified by crystal violet staining after 24 h of static incubation at 37°C. (A) The ring corresponding to robust biofilm formation characteristic of the atsR mutant is indicated by an arrow. (B) The extent of crystal violet retention by adherent bacteria was measured by OD₅₄₀. Data shown are the means of three independent experiments done in triplicate. Error bars represent the standard deviations. Significant differences were determined using unpaired t tests. The three asterisks indicate that the P value is 0.0001.