pH delta mid3

Edge evidence

• wide pH-homeostasis flexibility produces pH delta mid3 METPO:2000202

  Wide pH-homeostasis flexibility yields a 4–5 pH-unit pH-delta breadth.

  • DOI:10.1038/nrmicro2549 pH homeostasis Supports wide pH-homeostasis flexibility as the basis of a wide breadth.
• pH delta mid3 is a pH delta rdfs:subClassOf

  pH delta mid3 is a quantitative bin of the pH-delta phenotype.

  • DOI:10.1038/nrmicro2549 external pH Supports the 4–5 unit breadth as a value within the pH-delta distribution.
• external alkaline pH increases reliance on electrogenic Na+/H+ antiport

  High external pH increases reliance on electrogenic Na+/H+ antiport for cytoplasmic pH homeostasis.

  • DOI:10.1038/nrmicro2549 Multiple Na+/H+ and K+/H+ antiporters are critical for alkaline homeostasis, driven by membrane potential.
• regulation of membrane potential and pH gradient supports cytoplasmic pH maintenance

  Regulation of Delta-psi and Delta-pH supports maintenance of cytoplasmic pH across external pH changes.

  • DOI:10.1038/nrmicro2549 PMF (Delta-pH and Delta-psi) is central to pH homeostasis; neutralophiles keep cytoplasmic pH near 7.5 across external pH ~5.5-9.0.
• proton-pumping respiratory complexes contribute to proton motive force

  Proton-pumping respiratory complexes contribute to the PMF used for pH homeostasis.

  • DOI:10.1038/nrmicro2549 Cells use primary proton pumps including respiratory-chain pumps to create PMF for transport and pH regulation.
• F0F1-ATPase contributes to cytoplasmic pH maintenance RO:0002326

  F0F1-ATPase can extrude protons and contributes to pH homeostasis under acid stress.

  • DOI:10.1093/femsre/fuad033 F1Fo-ATPase hydrolytic activity can drive H+ extrusion; key regulator in low-pH contexts.
• cytoplasmic phosphate buffering capacity stabilizes intracellular pH stability

  Cytoplasmic phosphate buffering capacity stabilizes intracellular pH.

  • DOI:10.1093/femsre/fuad033 At pH ~7.2 only ~10 free protons present; cytoplasmic phosphate buffering (~100 mM) makes buffering essential.
• amino-acid decarboxylation pathways contributes to proton motive force RO:0002326

  Amino-acid decarboxylation pathways consume protons and contribute to PMF and intracellular pH control.

  • DOI:10.1093/femsre/fuad033 Decarboxylation releases ~20 kJ/mol that can be stored as PMF; decarboxylation pathways are key pH regulators.
• membrane lipid composition shifts reduces membrane proton permeability METPO:2000017

  Membrane lipid composition shifts reduce proton permeability.

  • DOI:10.3389/fmicb.2022.1034164 Membrane composition adjustments limit proton permeability and alter phospholipid headgroups under high pH.