pH delta mid1

Edge evidence

• moderate pH-homeostasis flexibility produces pH delta mid1 METPO:2000202

  Moderate pH-homeostasis flexibility yields a 2–3 pH-unit pH-delta breadth.

  • DOI:10.1038/nrmicro2549 pH homeostasis Supports moderate flexibility as the basis of an intermediate breadth.
• pH delta mid1 is a pH delta rdfs:subClassOf

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

  • DOI:10.1038/nrmicro2549 external pH Supports the 2–3 unit breadth as a value within the pH-delta distribution.
• F0F1-ATPase contributes to cytoplasmic pH homeostasis RO:0002326

  Under acid stress F0F1-ATPase hydrolyzes ATP to consume/export intracellular H+, maintaining cytoplasmic pH.

  • DOI:10.3390/microorganisms12091774 F0F1-ATPase under acid stress hydrolyzes ATP to consume intracellular H+ to maintain homeostasis; broad pH-homeostasis mechanism.
• glutamine/glutamate decarboxylation pathway consumes intracellular proton (H+) biolink:consumes

  Coupled glutamine conversion and glutamate decarboxylation consume two intracellular H+, enhancing acid resistance.

  • DOI:10.3390/microorganisms12091774 Glutamine conversion and glutamate decarboxylation can act together to consume two H+; pathway-level proton-consumption module.
• YbaS glutaminase produces ammonia METPO:2000202

  YbaS glutaminase converts glutamine to glutamate and releases ammonia, which neutralizes intracellular protons.

  • DOI:10.3390/microorganisms12091774 The glutaminase YbaS converts glutamine to glutamate and releases ammonia, which neutralizes intracellular protons.
• membrane saturated fatty acid content decreases proton diffusion across membrane RO:0002212

  A higher proportion of saturated membrane fatty acids limits passive proton diffusion across the membrane.

  • DOI:10.1128/aem.00569-24 Conversion of unsaturated to saturated fatty acids limits proton diffusion; broadly plausible membrane-permeability mechanism.
• oxidative phosphorylation / electron transport chain maintains proton motive force

  Upregulated oxidative phosphorylation/ETC increases proton export and maintains the proton motive force, helping resist cytoplasmic pH decreases.

  • DOI:10.3390/microorganisms12081565 Upregulation of oxidative phosphorylation genes increases proton export rate and maintains a proton motive force that helps cells resist cytoplasmic pH decreases under mild acid (pH 6.0) growth.
• proton motive force contributes to cytoplasmic pH homeostasis RO:0002326

  A maintained proton motive force supports cytoplasmic pH homeostasis under acid stress.

  • DOI:10.3390/microorganisms12081565 PMF generated/maintained by oxidative phosphorylation helps cells resist cytoplasmic pH decreases.
• cytoplasmic pH homeostasis contributes to moderate pH-homeostasis flexibility RO:0002326

  Cytoplasmic pH homeostasis modules collectively underlie moderate pH-homeostasis flexibility.

  • DOI:10.3390/microorganisms12091774 Proton-consumption and proton-export modules maintaining cytoplasmic pH underpin homeostatic flexibility across a few pH units.