Electron probe analysis, X-ray mapping, and electron energy-loss spectroscopy of calcium, magnesium, and monovalent ions in log-phase and in dividing Escherichia coli B cells

J Bacteriol. 1986 Sep;167(3):935-9. doi: 10.1128/jb.167.3.935-939.1986.

Abstract

The elemental composition of individual cells of rapidly frozen and cryosectioned Escherichia coli B was measured with electron optical microanalytic methods. The Ca content was high (26.2 mmol/kg) in a 10-nm-wide region of the cell envelope. Amounts of cytoplasmic Ca in actively dividing cells were significantly higher (32.6 mmol/kg [dry weight]) than in the log-phase (1.5 mmol/kg) cells. Cellular Mg was 205 mmol/kg (dry weight) and it was uniformly distributed throughout the cell. Cells washed in distilled water before freezing lost monovalent ions (Na, Cl, and K), but the membrane-bound Ca and cellular Mg were not reduced, indicating that cellular Mg and membrane Ca are more tightly bound.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Calcium / analysis*
  • Cell Division
  • Cell Membrane / analysis
  • Chlorine / analysis
  • Cytoplasm / analysis
  • Electron Probe Microanalysis / methods
  • Escherichia coli / analysis*
  • Magnesium / analysis*
  • Phosphorus / analysis
  • Potassium / analysis
  • Sodium / analysis
  • Sulfur / analysis

Substances

  • Phosphorus
  • Chlorine
  • Sulfur
  • Sodium
  • Magnesium
  • Potassium
  • Calcium