A low pH-inducible, PhoPQ-dependent acid tolerance response protects Salmonella typhimurium against inorganic acid stress.

ABSTRACT: The acid tolerance response enables Salmonella typhimurium to survive exposures to potentially lethal acidic environments. The acid stress imposed in a typical assay for acid tolerance (log-phase cells in minimal glucose medium) was shown to comprise both inorganic (i.e., low pH) and organic acid components. A gene previously determined to affect acid tolerance, atbR, was identified as pgi, the gene encoding phosphoglucoisomerase. Mutations in pgi were shown to increase acid tolerance by preventing the synthesis of organic acids. Protocols designed to separate the stresses of inorganic from organic acids revealed that the regulators sigma38 (RpoS), Fur, and Ada have major effects on tolerance to organic acid stress but only minor effects on inorganic acid stress. In contrast, the two-compo

SUBMITTER: Bearson BL 

PROVIDER: S-EPMC107183 | biostudies-literature | 1998 May

REPOSITORIES: biostudies-literature