Determination of turgor pressure in Bacillus subtilis: a possible role for K+ in turgor regulation

J Gen Microbiol. 1990 Dec;136(12):2521-6. doi: 10.1099/00221287-136-12-2521.


The effects of hypersaline treatment (osmotic upshock) on cell water relations were examined in the Gram-positive bacterium Bacillus subtilis using particle size analysis. Application of the Boyle-van't Hoff relationship (cell volume versus reciprocal of external osmolality) permitted direct determination of turgor pressure, which was approximately 0.75 osmol kg-1 (1.9 MPa) in exponentially growing bacteria in a defined medium. The abolition of turgor pressure immediately after upshock and the subsequent recovery of turgor were investigated. Recovery of turgor was K+ dependent. Calculation of turgor by an alternative method involving spectrophotometric analysis of shrinkage gave somewhat lower estimates of turgor pressure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / metabolism
  • Bacillus subtilis / physiology*
  • Osmotic Pressure
  • Potassium / metabolism*
  • Spectrum Analysis


  • Potassium