FIGURE 4.

Pyruvate’s role in persister cell formation, and PYR and PF increase bacterial killing activity of strain A118. (A) Percentage of surviving cells in LB, PF, LB + 1% PYR, and PF + 1% PYR of strain A118, (B) strain A42, and (C) strain AB5075. Persister cells are defined as the number of surviving cells after treatment with OFX divided by the number of surviving cells after treatment with water. Statistical significance (^∗P < 0.05; ^∗∗P < 0.005) was determined using unpaired t-test (n = 3), comparing LB vs. PYR and PF vs. PF + PYR. (D) Bacterial killing assay using Escherichia coli TOP10-TET (prey) and A118 (predator) grown under the different treatments (LB, PF, LB + 1% PYR, and PF + 1% PYR). Differences in survival of bacterial (E. coli-TET prey) colonies are shown in log₂CFU/ml. Statistical significance was determined using one-way ANOVA analysis (^∗P < 0.05; ^∗∗P < 0.01; ^∗∗∗P < 0.005; ^∗∗∗∗P < 0.0001), and experiments were performed in triplicates.