FIG 1.

Addition of nitrate alters the biomass and expression of curli and cellulose in S. Typhimurium biofilms. (A) Biofilm pellicles of wild-type S. Typhimurium grown with or without NaNO₃ for 72 h at 28°C were stained with a crystal violet assay. (B) Colony biofilms of wild-type S. Typhimurium, csgBA mutant, and bcsE mutant spotted onto Congo red/Coomassie blue indicator plates supplemented with 0 mM, 40 mM, or 100 mM NaNO₃. (C) Western blot of extracts of wild-type S. Typhimurium, csgBA mutant, and bcsE mutant grown in 0 mM, 40 mM, or 100 mM NaNO₃ for CsgA.