Fig. 7
Membrane potential measurements for WT and mutant L. reuteri strains under acidic conditions. L. reuteri cells were treated as in Fig. 6, except the pH of assay buffers was lowered to 5.3. N = 4 biological replicates per group. Two-way ANOVA with Tukey’s multiple comparison test. Error bars represent ± SEM. Under acidic conditions, all EriC and EriC2 mutant strains exhibited a significantly positive polarization relative to WT, HdcA Stop, and HdcP stop cells. Additionally, within the PBS, d-His, and l-His treatment groups, significant differences were observed for the strains marked above (*P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, n.s. not significant)