title: An L-form of Staphylococcus aureus adapted to a brain heart infusion medium without osmotic stabilizers.
abstract: An L-form derived from halotolerant Staphylococcus aureus Tasaki was adapted to growth in a brain heart infusion medium without any supplemental osmotically protective solutes (360 mOsm/kg). This L-form had no chemically detectable peptidoglycan residues on its surface. Electron microscopic observations confirmed morphologically the absence of the structures and also of other osmotically protective polymers within or exterior to the cytoplasmic membrane. The osmotic stability and susceptibility to bacitracin, D-cycloserine, and vancomycin of the L-form adapted to growth in 360 mOsm osmotically unprotective medium was higher than that of the L-form grown in 1,950 mOsm supplemented with 4.5% NaCl. The adapted L-form tended to be more sensitive to almost all of the antibiotics examined, other than the inhibitors for cell wall-synthesis, than the original L-form strain requiring osmotic protection for growth. Chemical analysis of the membrane of the adapted L-form indicated 16.3% total lipids and 20.6% proteins by dry weight of the membrane, and it contained larger amounts of lipid phosphorus (20.0 microgram/mg).
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis; D002462:Cell Membrane / Q000032:analysis; D003470:Culture Media; D007740:L Forms / Q000187:drug effects / Q000254:growth & development*; D008055:Lipids / Q000032:analysis; D008565:Membrane Proteins / Q000032:analysis; D009994:Osmolar Concentration; D009996:Osmotic Fragility; D013211:Staphylococcus aureus / Q000166:cytology* / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D003470:Culture Media; D008055:Lipids; D008565:Membrane Proteins