neutrophilic

Edge evidence

• near-neutral external pH enables neutrophilic RO:0002327

  Neutrophiles grow optimally when external pH is near neutrality.

  • DOI:10.1038/nrmicro2549 external pH values outside the cytoplasmic pH Review supports growth constraints around cytoplasmic pH compatibility.
• cytoplasmic pH homeostasis enables neutrophilic RO:0002327

  Growth near neutral pH still requires active maintenance of internal pH.

  • DOI:10.1038/nrmicro2549 bacterial pH homeostasis is a cell-wide physiological process Supports pH homeostasis as central to bacterial growth.
• proton motive force interacts with cytoplasmic pH homeostasis biolink:interacts_with

  pH regulation is linked to proton motive force and bioenergetics.

  • DOI:10.1016/j.tim.2007.02.005 intrinsically linked to cellular bioenergetics Supports coupling of pH gradients and bioenergetics.
• cation/proton antiporter contributes to cytoplasmic pH homeostasis RO:0002326

  Cation/proton antiporters help regulate ion and pH balance.

  • DOI:10.3390/ijms21124566 maintaining ion and pH homeostasis Supports cation/proton antiport as a general pH-homeostasis mechanism.
• external acidic pH increases cytoplasmic proton influx RO:0002213

  Low external pH increases H+ entry into the cytoplasm, challenging neutral pH homeostasis.

  • DOI:10.1128/msystems.01037-23 At low pH, H+ can permeate into the cytoplasm via protonated water chains, ion channels, or damaged membranes (general for neutralophilic bacteria).
• cytoplasmic buffering capacity contributes to intracellular pH RO:0002326

  Proton sequestration by cytoplasmic buffers stabilizes intracellular pH and protects enzyme function.

  • DOI:10.1128/msystems.01037-23 Protons can be sequestered by side-chains of proteins, inorganic phosphates, polyphosphates, or polyamines (general for neutralophiles).
• amino-acid decarboxylation contributes to cytoplasmic pH homeostasis RO:0002326

  Decarboxylation directly removes H+ from the cytoplasm, raising internal pH.

  • DOI:10.3390/antibiotics12091474 The decarboxylation of amino acids is an enzyme-catalyzed reaction that consumes protons (general acid-tolerance mechanism in neutralophiles).
• amino-acid decarboxylation contributes to proton motive force RO:0002326

  Charge-differential substrate/product antiport plus proton consumption couples pH homeostasis to PMF generation.

  • DOI:10.1093/femsre/fuad033 The chemistry of the decarboxylation reaction requires a proton, and the equivalent of 1 proton is pumped per molecule decarboxylated (general mechanism).
• F1F0-ATPase proton pump contributes to cytoplasmic pH homeostasis RO:0002326

  ATP-dependent proton transport helps restore cytoplasmic pH under acid challenge.

  • DOI:10.3390/antibiotics12091474 Common mechanisms involved in bacterial acid tolerance include the F1-F0-ATPase proton pump (general).