title: Highly phosphorylated core oligosaccharide structures from cold-adapted Psychromonas arctica.
abstract: Many cold habitats contain plenty of microorganisms that represent the most abundant cold-adapted life forms on earth. These organisms have developed a wide range of adaptations that involve the cell wall of the microorganism. In particular, bacteria enhance the synthesis of unsaturated fatty acids of membrane lipids to maintain the membrane fluidity, but very little is known about the adaptational changes in the structure of the lipopolysaccharides (LPSs), the main constituent of the outer leaflet of the outer membrane of Gram-negative bacteria. The aim of this study was to investigate the chemical structure of these LPSs for insight into the temperature-adaptation mechanism. For this objective, the cold-adapted Psychromonas arctica bacterium, which lives in the arctic sea-water near Spitzbergen (Svalbard islands, Arctic) was cultivated at 4 degrees C. The lipooligosaccharides (LOSs) were isolated and analysed by means of chemical analysis and electrospray ionisation high-resolution Fourier transform mass spectrometry. The LOS was then degraded either by mild hydrazinolysis (O-deacylation) or with hot 4 M KOH (N-deacylation). Both products were investigated in detail by using 1H and 13C NMR spectroscopy and mass spectrometry. The core consists of a mixture of species that differ because of the presence of nonstoichiometric D-fructose and/or D-galacturonic acid units.
authors.affiliation: Dipartimento di Chimica Organica e Biochimica, Università Federico II di Napoli, Complesso Universitario Monte S. Angelo, Via Cintia 4, 80 126 Napoli, Italy. corsaro@unina.it
authors.forename: Maria M
authors.initials: MM
authors.lastname: Corsaro
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Pieretti
authors.forename: Buko
authors.initials: B
authors.lastname: Lindner
authors.forename: Rosa
authors.initials: R
authors.lastname: Lanzetta
authors.forename: Ermenegilda
authors.initials: E
authors.lastname: Parrilli
authors.forename: Maria L
authors.initials: ML
authors.lastname: Tutino
authors.forename: Michelangelo
authors.initials: M
authors.lastname: Parrilli
mesh_terms: D000222:Adaptation, Physiological; D018441:Biofilms; D003080:Cold Temperature; D020563:Gammaproteobacteria / Q000737:chemistry* / Q000502:physiology*; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010766:Phosphorylation; D013696:Temperature
chemical_list: D008070:Lipopolysaccharides; C023023:lipid-linked oligosaccharides