Fig. 1.

pH-dependent inhibition of S. mutans GS5 biofilm formation by L-arginine. Diluted S. mutans GS5 cultures and test reagents were mixed at 1:1. After the mixtures were cultured anaerobically at 37 °C for 24 h, S. mutans biofilms that had formed at the bottom of the microwells were quantified by crystal violet staining. Saline (S), 10 mM citrate pH3.5 (CA3.5) or 0.5 M L-arginine solution adjusted with 10 mM citrate buffer to a pH between 3.5 and 7.0 (indicated as LA3.5-LA7.0) were used as test reagents. The data are expressed as means ± standard deviation. ^* Significantly different from saline (p < 0.05), ^** Significantly different from 10 mM citrate (pH3.5) (p < 0.05)