FIG. 7.

Autoaggregation of the gtfB mutant. (A) Autoaggregation. P. gingivalis cells were anaerobically grown in BHI broth at 37°C overnight. The optical densities at 600 nm of bacterial cultures of 33277 (wild type), KDP400 (gtfB), and KDP402 (gtfB/gtfB⁺) were 1.92 ± 0.05, 0.12 ± 0.00, and 1.89 ± 0.10, respectively. (B) Hydrophobicity. The graph shows the percentages of cells partitioning into the hydrophobic solvent n-hexadecane. **, P < 0.05. (C) Transmission electron microscopic images of 33277 (wild type) and KDP400 (gtfB). The cells were stained with uranium acetate and lead citrate.