FIGURE 3.

Curli but no cellulose is required for biofilm formation. (A) Biofilm formed by S. Typhimurium SV5015 (wt) and its mutant derivatives csgB, csgD, bcsAE, adrA, adrA bcsAE in MM and CFA. Biofilms attached to the plastic surface were stained with CV after 72 h incubation at 25°C. The type of biofilm formed by each mutant in the specified media is indicated with a B (bottom), P (pellicle), and N (no biofilm). (B) Production of cellulose by the wt strain in minimal media (MM) and rich media (CFA) after growing the cells for 72 h at 25°C with gentle shaking in the presence of 10 mM of CF. Fluorescence was visually observed under UV (top panel) and quantified with a fluorimeter. The results were normalized according the number of cells and expressed as arbitrary fluorescence units (bottom panel). ^∗∗p < 0.005.