Determination of turgor pressure in Bacillus subtilis: a possible role for K+ in turgor regulation.
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.
Whatmore
A M
AM
Department of Biological Sciences, University of Dundee, UK.
Reed
R H
RH
D001412:Bacillus subtilis / Q000378:metabolism / Q000502:physiology*; D009997:Osmotic Pressure; D011188:Potassium / Q000378:metabolism*; D013057:Spectrum Analysis
D011188:Potassium