title: Increased outer membrane ornithine-containing lipid and lysozyme penetrability of Paracoccus denitrificans grown in a complex medium deficient in divalent cations.
abstract: Paracoccus denitrificans grown in a complex medium was highly susceptible to lysozyme, in contrast to cells grown in a complex medium supplemented with Mg2+ and Ca2+ or in a succinate-salts medium. The complex medium was deficient in divalent cations needed for optimum outer membrane stability. The major change in molecular compositions of outer membranes isolated from cells grown under the different conditions was a higher ratio of ornithine-containing lipid to phospholipid in complex-medium-grown cells (0.63) than in cells grown in complex medium with Mg2+ and Ca2+ (0.22) or in succinate-salts medium (0.14). We suggest that the dipolarionic ornithine-containing lipid is less dependent than acidic phospholipids on divalent cations for its incorporation into the outer membrane.
authors.affiliation: Department of Biological Sciences, Illinois State University, Normal 61761.
authors.forename: S
authors.initials: S
authors.lastname: Wee
authors.forename: B J
authors.initials: BJ
authors.lastname: Wilkinson
mesh_terms: D002118:Calcium / Q000494:pharmacology*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000032:analysis / Q000187:drug effects / Q000378:metabolism; D002463:Cell Membrane Permeability; D003470:Culture Media; D008274:Magnesium / Q000494:pharmacology*; D008563:Membrane Lipids / Q000032:analysis / Q000378:metabolism*; D009113:Muramidase / Q000494:pharmacology*; D009952:Ornithine / Q000032:analysis; D010230:Paracoccus / Q000032:analysis / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D003470:Culture Media; D008563:Membrane Lipids; D009952:Ornithine; D009113:Muramidase; D008274:Magnesium; D002118:Calcium