Figure 3.

Thiamine-related genes affected tolerance to acid, oxidative, and osmotic stresses of PstDC3000. (A) PstDC3000 wild type, the thiD/E, thiS/G, thiD/E/S/G, and apbE mutant cells of overnight cultures in KB were washed and resuspended to OD₆₀₀ = 0.01 in KB liquid medium with pH 5.5. The phenotype was observed after incubation at 28°C for 24 h and bacterial growth was monitored by measuring OD₆₀₀. (B) All the mutant cells were grown in KB liquid medium with 0.5 M NaCl and incubated at 28°C for 24 h. (C) All the mutant cells were grown in KB liquid medium with 0.5 mM hydrogen peroxide (H₂O₂) and incubated at 28°C for 24 h. (D) All the complementation strains were grown in KB liquid medium with pH 5.5. (E) All the complementation strains were grown in KB liquid medium with 0.5 M NaCl. (F) All the complementation strains were grown in KB liquid medium with 0.5 mM H₂O_2. The solid line represents mutant strains; the dashed line represents complementation strains; and the vertical bars represent SDs. Experiments were performed in triplicate and repeated three times. Statistical tests were performed and statistically significant differences were determined by one-way ANOVA and P-values were < 0.05 [an asterisk (*) indicates P < 0.05, mutant and complementation strains vs. the WT PstDC3000].