Fig. 1

M. smegmatis containing pBEN, pMPR, or pFPV27 were grown to mid-logarithmic phase in pH 7.0 media and the pH was then shifted to pH 4.0 through 7.0 for a 3 h exposure. Fluorescence and OD₆₀₀ were measured. AFU is adjusted fluorescence units and calculated by fluorescence units/optical density units at 600 nm. The data are presented as the mean ± the standard deviation. *P < 0.03, significantly different from pH 4.5; ^oP < 0.04, significantly different from pH 4.3. There was no statistical difference of cells bearing pMPR at pH 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, and 5.0 compared to pH 4.3. Statistical difference was defined as a P < 0.05. The sample size was 3 and represents biological replicates