FIG. 3.

Overexpression of vpsS activates biofilm formation. (A) Quantitative comparison of biofilm formation by wild-type strains harboring the vector or pvpsS. Strains were grown for 8 h in LB medium supplemented with ampicillin in the absence (open bars) or presence (filled bars) of arabinose at 30°C under static conditions. Crystal violet-stained biofilms formed in the wells of polyvinyl chloride microtiter plates are also shown. The error bars indicate standard deviations of eight technical replicates. The results of one representative experiment of two biological replicates are shown. (B) CSLM images of horizontal (xy) and vertical (xz) projections of biofilm structures formed by the wild-type strain (Wt), the ΔvpsS mutant, and wild-type strains carrying the vector or pvpsS. Strains were grown for the times indicated in 2% LB medium in the presence or absence of ampicillin and 0.2% arabinose at room temperature. Bars = 40 μm.