Fig 8. The ΔnprB mutation had no significant effect on biofilm formation.

(A) Colony biofilms of the wild-type and ΔnprB mutant strains. These strains were grown at 30°C for 48 h on 2×SG. Scale bar, 2 mm. (B) The ΔnprB mutation had no significant effect on the composition of the extracellular proteins of colony biofilms. Colonies grown at 30°C for 48 h on 2×SG were suspended in SDS-PAGE sample buffer (62.5 mM Tris-HCl (pH 6.8), 1% SDS, 10% glycerol, 2.5% 2-mercaptoethanol, 2 mM PMSF, and 5 mM EDTA) and boiled for 2 min. After centrifugation, the supernatants were subjected to SDS-PAGE. Protein bands were visualized via Coomassie brilliant blue (CBB) staining. The size of protein molecular weight markers (lanes M) is indicated on the left side. The experiment was done twice, and the typical example was shown.