Figure 6.

Effect of quercetin on hydrophobicity and aggregation. (a) Bacterial cells cultured in BHI with quercetin were washed and re-suspended in PUM buffer. 0.4 mL of hexadecane was added to 2 mL of the cell suspensions in tubes. After vortexed for 60 s and then incubated for 15 min at room temperature, the OD_550nm of the aqueous phase was measured and the hydrophobic activity was calculated. (b) P. gingivalis were cultured anaerobically at 37 °C for 48 h in BHI broth, harvested and re-suspended in PBS to an OD_600nm of 1.0. After 3 h, aggregation was calculated by measuring the decrease in OD_600nm of each suspension at 37 °C. Bars denoted by (*), (**) and (****) indicate significant difference at p < 0.05, p < 0.01 and p < 0.0001, respectively by one-way analysis of variance (ANOVA) with Dunnett’s post hoc test.