FIG. 3.

Analyses of various phenotypes of a VtpR-deficient mutant of V. tubiashii strain RE22. Extracellular protease production (A), protease zymogram profile (B), toxicity to oyster larvae (C), extracellular hemolysin production (D), and swarming motility (E) were compared. Bacteria were grown in LB medium supplemented with 1% NaCl at 30°C and harvested at the stationary phase (OD₆₀₀ of ∼3.2). For the hemolysin assay, cells were also harvested at the late log phase (OD₆₀₀ of ∼1.8). For the toxicity assay, filter-sterilized supernatants were added to a final concentration of 0.5%. The error bars indicate the standard deviations (n = 3). For motility assay, LB soft agar supplemented with 3% NaCl was used. WT, wild type.