FIG. 1.

The influence of rpoS, pgi, and growth on citrate on the ATR. Cells were grown to mid-log phase (approximately 2 × 10⁸ cells per ml) in minimal EG medium (pH 7.7). When indicated, E medium with citrate was used as the carbon source. Unadapted cell cultures were adjusted to pH 3, and samples were taken for viable counts at time zero and 60 min and after acid challenge. Adapted cultures were adjusted from pH 7.7 to 4.4 for 1 h and then acid challenged for 1 h at pH 3. Wild-type UK1 (SF530), rpoS::Ap (JF2690), atbR (JF2733), rpoS atbR (JF2731), and rpoS pgi (JF2955) cells were assayed. The data are a representative sample of triplicate experiments.