FIG. 7.

Hya mutant survival under acid stress conditions. Anaerobic bottles containing citric acid-phosphate buffer at pH 4 were inoculated with 10⁸ wild-type (wt) or hya mutant cells that were grown anaerobically in LB overnight. Bottles were incubated for various times, as indicated, and samples were taken. Cells were enumerated by dilution plating on LB agar. Results are averages for at least four replicates.