FIG. 4.

Increased Psl production enhances cell-surface interactions and biofilm formation: results of microtiter dish attachment assays with biofilms stained with crystal violet after 30 min of attachment (A) or after 8 h of attachment (B). The images show crystal violet-stained microtiter dish wells after ethanol elution, and the released soluble crystal violet was also evaluated by determining the A₅₄₀ (the means of triplicate determinations are indicated below the wells). The arabinose concentrations used for Psl induction during growth of WFPA801 are indicated below the wells.