title: Unusual lipid composition of the gram-negative, freshwater, stalked bacterium Caulobacter bacteroides NP-105.
abstract: The extractable lipids of the gram-negative, stalked, freshwater bacterium Caulobacter bacteroides NP-105 account for about 9.5% by weight of dry cells, polar lipids comprising up to 95% of the total. The polar lipids consist of five glycolipids, namely, 1,2-diacyl-3-alpha-D-glucopyranosyl-sn-glycerol (I) (34% of the total), 1,2-diacyl-3-alpha-D-[6'-(1",2"-diacyl-sn-glycero-3-phospho)]glucopyranosyl-sn-glycerol (II) (7%), 1,2-diacyl-3-a-D-glucuronopyranosyl-sn-glycerol (III) (17%), 1,2-diacyl-3-alpha-D-(6'-sulfo)quinovopyranosyl-sn-glycerol (V) (9%), and 1,2-diacyl-3-alpha-D-[4'-(alpha-D-glucopyranosyl)] glucuronopyranosyl-sn-glycerol (VI) (28%), and one glycerophospholipid, 1,2-diacyl-sn-glycero-3-phosphoglycerol (IV) (5%). The main fatty acyls of the lipids are n-16:0, cis-18:1 omega7, and cis-11,12-methyleneoctadecanoic (lactobacillic) acid residue. Of the 6 lipids listed, only 3 (I, IV, and V) can be treated as widely encountered. However, sulfonic glycolipid V is a characteristic lipid component of photosynthetic organisms rather than non-photosynthetic ones. Phosphatidyl derivatives of glycosyldiacylglycerols of type II normally occur in gram-positive bacteria, among gram-negative bacteria they have been revealed only in two species of the Pseudomonas genus. Glucuronosyl and alpha-glucosyl-a-glucuronosyl diacylglycerols such as III and VI, respectively, are very rare lipids, the latter being found so far only in a Streptomyces strain.
authors.affiliation: Research Centre Hydrobios of Ministry of Health, Moscow, Russia.
authors.forename: S G
authors.initials: SG
authors.lastname: Batrakov
authors.forename: D I
authors.initials: DI
authors.lastname: Nikitin
authors.forename: V I
authors.initials: VI
authors.lastname: Sheichenko
authors.forename: A O
authors.initials: AO
authors.lastname: Ruzhitsky
mesh_terms: D016934:Caulobacter / Q000737:chemistry*; D002855:Chromatography, Thin Layer; D005227:Fatty Acids / Q000032:analysis; D006017:Glycolipids / Q000032:analysis; D008055:Lipids / Q000032:analysis / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy
chemical_list: D005227:Fatty Acids; D006017:Glycolipids; D008055:Lipids