FIG. 5.

Survival of serovar Typhimurium mutants in synthetic gastric fluid containing 10 mM lactic acid. SX 2 (wild type), SX 21 (rpoS), SX 46 (phoP), SB 270 (fur)m and SB 130 (pnp) were grown in minimal EG medium to an OD₆₀₀ of 0.4. Following acid adaptation at pH 4.4 for 1 h, the cells were washed and resuspended in an equal volume of synthetic gastric fluid containing 10 mM lactic acid. Viable counts were determined at 0, 30, and 60 min for determination of percent survival.