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