non halophilic

Edge evidence

• low-to-moderate salinity enables non halophilic RO:0002327

  Non-halophilic organisms do not require elevated salinity for growth.

  • DOI:10.1128/AEM.01934-12 soil-dwelling bacterium Bacillus subtilis Bacillus subtilis is used here as a non-halophilic model for salt stress responses rather than salt-requiring growth.
• high osmolarity regulates water flux across cytoplasmic membrane RO:0002211

  Hyperosmotic stress alters cellular water balance and can impair non-halophilic growth.

  • DOI:10.1128/AEM.01934-12 outflow of water, drop in turgor, and the ensuing growth arrest Supports high-osmolarity growth inhibition through water loss and turgor decrease.
• potassium ion mitigates water flux across cytoplasmic membrane METPO:2007407

  Rapid potassium accumulation helps adjust cytoplasmic osmotic potential after osmotic upshift.

  • DOI:10.1128/AEM.01934-12 initially importing substantial amounts of potassium ions Supports potassium uptake as an initial osmotic response.
• proline mitigates water flux across cytoplasmic membrane METPO:2007407

  Proline accumulation supports osmoadaptation under sustained high-osmolarity conditions.

  • DOI:10.1128/JB.00778-11 proline production is required Supports de novo proline synthesis in Bacillus subtilis osmotic defense.
• compatible-solute uptake systems imports proline METPO:2000208

  Uptake systems can import osmoprotectants that relieve high osmolarity.

  • DOI:10.1128/AEM.01934-12 osmotically controlled uptake systems Supports uptake systems for compatible solutes in Bacillus subtilis.
• proline enables tolerance of high osmolarity

  Proline acts as an osmoprotectant enabling survival or growth under salt stress without making salt a growth requirement.

  • DOI:10.1128/AEM.01934-12 proline as an osmoprotectant Supports proline-mediated protection in a non-halophilic bacterial model.
• osmotic upshift causes water efflux and cytoplasmic volume decrease biolink:causes

  Hypertonic stress drives rapid water efflux and cytoplasmic volume/turgor decrease.

  • DOI:10.1128/mmbr.00181-23 Under hypertonic stress water exits cells within milliseconds, causing cytoplasmic volume decreases up to ~50%, a rapid fall in turgor and increased ionic strength.
• osmotic upshift induces rapid potassium uptake

  Cells import large amounts of K+ as the primary emergency response to osmotic upshift.

  • DOI:10.1128/mmbr.00181-23 Cells commonly import large amounts of K+ during osmotic upshift; generic across non-halophilic bacteria.
• rapid potassium uptake requires counterion balancing by L-glutamate

  Glutamate is imported or synthesized as the counterion to balance accumulated K+ and maintain electroneutrality.

  • DOI:10.1128/mmbr.00181-23 Glutamate commonly imported or synthesized as the counterion to maintain electroneutrality during K+ accumulation.
• rapid potassium uptake promotes replacement by compatible solute accumulation

  High intracellular K+/ionic strength is mitigated by secondary accumulation of neutral compatible solutes that replace K+.

  • DOI:10.1128/mmbr.00181-23 Bacteria such as E. coli and B. subtilis accumulate/synthesize neutral compatible solutes to replace K+; compatible-solute accumulation is a secondary response following primary K+ accumulation.