FIG 3 .

Measurements of local pH near the export apparatus. (A) Measurements of the local pH of the pH-fliG (YVM1004) and ΔfliMN::tetRA pH-fliG (YVMN001) cells at external pH 7.0. The local pH was measured with more than 100 fluorescent spots. The pH distribution was fitted by a Gaussian function. P values were calculated using a two-tailed t test. All cells were incubated at 30°C in TB until the cells had reached an OD₆₀₀ of ca. 1.6 to 1.8. (B) Measurements of the local pH of the YVM1060 [pHluorin(M153R)-fliG fliR::Tn10, red line] cells at external pH 7.0. More than 200 spots were analyzed.