title: Isolation and structure determination of a novel compatible solute from the moderately halophilic purple sulfur bacterium Ectothiorhodospira marismortui.
abstract: The halophilic phototrophic bacterium Ectothiorhodospira marismortui produces three organic osmolytes to counterbalance the osmotic pressure of the surrounding medium: glycine betaine, sucrose, and a novel compound. This new compound, which accounts for approximately 30% of the cells' compatible solutes, was isolated and identified by mass spectrometry and nuclear magnetic resonance. It was characterized as N alpha-carbamoyl-L-glutamine 1-amide, an unusual amino acid derivative with no previous reference in the chemical literature. The relatively high cytoplasmic concentration of this compound (approximately 0.5 M) observed at all growth conditions suggests that it may serve a vital function as an osmoticum and/or protectant for Ectothiorhodospira marismortui in a saline environment.
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Federal Republic of Germany.
authors.forename: E A
authors.initials: EA
authors.lastname: Galinski
authors.forename: A
authors.initials: A
authors.lastname: Oren
mesh_terms: D002841:Chromatiaceae / Q000032:analysis* / Q000254:growth & development; D002852:Chromatography, Ion Exchange; D003124:Colorimetry; D005612:Freeze Drying; D005973:Glutamine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D015394:Molecular Structure; D009997:Osmotic Pressure
chemical_list: D005973:Glutamine; C069391:N(alpha)-carbamoylglutamine-1-amide