FIG 6.

Effects of different combinations of three AHLs on protease activity of V. coralliilyticus RE22Sm. Determination of protease activities of V. coralliilyticus RE22Sm strain treated with a single AHL (at the IC₅₀), various combinations of AHLs (each at the calculated IC₅₀), or an appropriate amount of methanol (ctrl) by measuring OD₄₄₂ of azopeptide from azocasein degradation caused by protease activity. Data are representative of two independent experiments. Each value is the average from three replicates. Error bars represent one standard deviation.