AlgR promotes biofilm formation and delays killing.

<p>(A) SK assays for <i>algR</i> deletion and overexpression strains. Loss of <i>algR</i> led to a small increase in virulence, while overexpression of pBADGr-<i>algR</i> or pBADGr-<i>algR</i>_D54A delayed killing at 0.05% L-arabinose. Asterisks indicate strains that were significantly different from PA14 + pBADGr by Gehan-Breslow-Wilcoxon test at p = 0.05 (p = 0.00833 with a Bonferroni correction), n = 3 trials. (B) Biofilm assays for <i>algR</i> deletion and overexpression strains. Microtiter plate biofilm assays were performed in liquid SK media over 24 h, in triplicate. Biofilms were stained with 1% crystal violet then solubilized in acetic acid. Loss of <i>algR</i> had no effect on biofilm formation. When grown at 0.05% L-arabinose, overexpression of pBADGr-<i>algR</i> or pBADGr-<i>algR</i>_D54A increased biofilm formation, p < 0.001. Significance was determined by one-way ANOVA followed by Dunnett post-test relative to WT, n = 3 trials.