title: Diversity of the polar lipids of the food-borne pathogen Listeria monocytogenes.
abstract: Listeria monocytogenes is a Gram-positive bacterium that can adapt to high salinity and cold. Because the membrane lipids may play a role in its survival and adaptation, we have examined the polar lipids of L. monocytogenes. Extraction of total lipids from L. monocytogenes yielded 7 +/- 1 mg/mL wet cells. Polar lipids represented 64% of total lipids and contained 9% lipid-phosphorus. Polar lipids were separated into 14 components by two-dimensional thin-layer chromatography. Eight components (88% of polar lipids) contained lipid-phosphorus; among these was one major component (34% of polar lipids). Two other phospholipids were ninhydrin-positive components and accounted for 15% of the polar lipids. Orcinol staining revealed two glyco- or sulfo-lipids accounting for 9% of polar lipids. Five components (4% of polar lipids) were amino components free of phosphorus. The major component contained 46% of its fatty acids as 15:0 anteiso, 24% as 17: 0 anteiso, and 11% as 15:0 iso. The fatty acid profile of the remaining polar lipids was variable, consisting primarily of 16:0, 18:0, 15:0 anteiso, and 17:0 anteiso. Their unsaturation level was < or = 20%; however, the major phosphoaminolipid component was 46% unsaturated. The ratios of 15:0 anteiso/17:0 anteiso and 15:0 anteiso/15:0 iso were similar in all classes, averaging 1.5 and 4.5, respectively. Since the adaptation process to stressful environments involves activation of a membrane transport system for the protectant glycine betaine, the membrane lipids may play a role in enabling transport.
authors.affiliation: Department of Food Science and Technology, University of California, Davis 95616, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Mastronicolis
authors.forename: J B
authors.initials: JB
authors.lastname: German
authors.forename: G M
authors.initials: GM
authors.lastname: Smith
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004396:Coloring Agents; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D008089:Listeria monocytogenes / Q000737:chemistry* / Q000502:physiology; D008563:Membrane Lipids / Q000032:analysis*; D009555:Ninhydrin; D019308:Palmitic Acid / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012118:Resorcinols; D013229:Stearic Acids / Q000032:analysis
chemical_list: D004396:Coloring Agents; D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D008563:Membrane Lipids; D012118:Resorcinols; D013229:Stearic Acids; D010758:Phosphorus; D019308:Palmitic Acid; C031183:stearic acid; C005282:orcinol; D009555:Ninhydrin