Figure 3.

Biofilm formation by homotypic P. gingivalis 33277, ECF sigma factor mutant and complemented mutant strain. The strains were grown on enriched BHI broth anaerobically at 37°C in collagen type-I-coated 12-well flat-bottom microplates. After 48 h of cultivation, the organized biofilm mass was evaluated by staining with crystal violet. (a) Biofilm formation of 33277, PGN_0274 mutant and the complemented mutant strain were compared. (b) Biofilm formation of 33277, PGN_1740 mutant and the complemented mutant strain were compared. Biofilm formation determined by crystal violet staining and adjusted for growth (A₆₀₀ units per OD₆₆₀ unit). The data shown are mean ± SD of triplicate experiments. *, p < 0.05, and ***, p < 0.001, by a one-way ANOVA Test/Dunnett’s Multiple Comparison Test.