title: Turnover of phospholipids in an unsaturated fatty acid auxotroph of Escherichia coli.
abstract: The membrane phospholipids of an unsaturated fatty acid auxotroph of Escherichia coli were found to undergo turnover. These phospholipids were excreted into the culture medium, and were replaced in the cell with newly synthesized phospholipids. Phospholipids of growing cells supplemented with elaidic acid underwent rapid turnover, while those of cells supplemented with oleate, or cis-vaccenate plus palmitoleate, underwent slow turnover. Starvation for required amino acids stimulated this turnover in the latter two cases. Protein was also lost from growing cells. However, after amino acid starvation this loss ceased while phospholipid turnover continued. Electron micrographs of growing cells indicated that large pieces of membrane-like material were separating from the cell surface.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D002247:Carbon Isotopes; D002462:Cell Membrane / Q000378:metabolism*; D002470:Cell Survival; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D003470:Culture Media; D004492:Edetic Acid / Q000494:pharmacology; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism*; D008055:Lipids / Q000302:isolation & purification; D008854:Microscopy, Electron; D009113:Muramidase / Q000494:pharmacology; D009829:Oleic Acids / Q000378:metabolism; D010743:Phospholipids / Q000096:biosynthesis / Q000378:metabolism*; D013501:Surface-Active Agents / Q000494:pharmacology; D013997:Time Factors; D014316:Tritium
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D002247:Carbon Isotopes; D003470:Culture Media; D005231:Fatty Acids, Unsaturated; D008055:Lipids; D009829:Oleic Acids; D010743:Phospholipids; D013501:Surface-Active Agents; D014316:Tritium; D004492:Edetic Acid; D009113:Muramidase