pH range mid1

Edge evidence

• baseline pH homeostasis enables pH range mid1 RO:0002327

  Baseline pH-homeostasis enables growth across pH 6–7.

  • DOI:10.1038/nrmicro2549 pH homeostasis Supports baseline pH-homeostasis as the neutrophilic range mechanism.
• pH range mid1 is a pH range rdfs:subClassOf

  pH range mid1 is a quantitative bin of the pH-range phenotype.

  • DOI:10.1038/nrmicro2549 external pH Supports the pH 6–7 range as a value within the pH-range distribution.
• proton motive force enables cytoplasmic pH homeostasis RO:0002327

  PMF (membrane potential) is required to maintain cytoplasmic pH homeostasis.

  • DOI:10.1103/PRXLife.2.043015 Terradot et al. 2024: decreasing the PMF's strength impairs the cells' ability to maintain pH.
• cytoplasmic pH homeostasis enables pH range mid1 RO:0002327

  Maintaining near-neutral cytoplasmic pH supports the neutrophilic pH 6-7 growth range.

  • DOI:10.1103/PRXLife.2.043015 Cytoplasmic pH held near neutral underlies the neutralophile growth range.
• cation/proton antiporters determines cytoplasmic pH homeostasis

  Transporter repertoire (ClcA/NhaB/NhaA-like antiporters) sets the external-pH boundaries over which cytoplasmic pH ~7 is maintained.

  • DOI:10.1103/PRXLife.2.043015 Terradot et al. 2024: ClcA-like ~pHe 2-5, NhaB-like ~5-9, NhaA-like ~9-12 maintain pHi ~7.
• acid challenge positively regulates respiratory proton-pumping complexes

  Under acid challenge cells upregulate proton-pumping respiratory complexes (and downregulate ATP synthase) to support pH homeostasis.

  • DOI:10.1038/nrmicro2549 Krulwich et al. 2011: under acid challenge E. coli up-regulates proton-pumping respiratory complexes and down-regulates ATP synthase.
• respiratory proton-pumping complexes enables baseline pH homeostasis RO:0002327

  Proton-pumping respiratory activity contributes to baseline pH homeostasis on the acidic side of the range.

  • DOI:10.1038/nrmicro2549 Krulwich et al. 2011: proton extrusion supports cytoplasmic pH maintenance under acid challenge.
• alkaline challenge positively regulates cation/proton antiporters

  Under alkaline challenge cells activate cation/proton antiporters and F1Fo-ATP synthase proton-capture to support pH homeostasis.

  • DOI:10.1038/nrmicro2549 Krulwich et al. 2011: under alkaline stress cells activate inward proton transport via cation/proton antiporters and increase ATP synthase expression.