title: The lipidome of the photosynthetic bacterium Rhodobacter sphaeroides R26 is affected by cobalt and chromate ions stress.
abstract: A detailed characterization of membrane lipids of the photosynthetic bacterium Rhodobacter (R.) sphaeroides was accomplished by thin-layer chromatography coupled with matrix-assisted laser desorption ionization mass spectrometry. Such an approach allowed the identification of the main membrane lipids belonging to different classes, namely cardiolipins (CLs), phosphatidylethanolamines, phosphatidylglycerols (PGs), phosphatidylcholines, and sulfoquinovosyldiacylglycerols (SQDGs). Thus, the lipidomic profile of R. sphaeroides R26 grown in abiotic stressed conditions by exposure to bivalent cobalt cation and chromate oxyanion, was investigated. Compared to bacteria grown under control conditions, significant lipid alterations take place under both stress conditions; cobalt exposure stress results in the relative content increase of CLs and SQDGs, most likely compensating the decrease in PGs content, whereas chromate stress conditions result in the relative content decrease of both PGs and SQDGs, leaving CLs unaltered. For the first time, the response of R. sphaeroides to heavy metals as Co(2+) and CrO4 (2-) is reported and changes in membrane lipid profiles were rationalised.
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70126, Bari, Italy.
authors.forename: Cosima Damiana
authors.initials: CD
authors.lastname: Calvano
authors.forename: Francesca
authors.initials: F
authors.lastname: Italiano
authors.forename: Lucia
authors.initials: L
authors.lastname: Catucci
authors.forename: Angela
authors.initials: A
authors.lastname: Agostiano
authors.forename: Tommaso R I
authors.initials: TR
authors.lastname: Cataldi
authors.forename: Francesco
authors.initials: F
authors.lastname: Palmisano
authors.forename: Massimo
authors.initials: M
authors.lastname: Trotta
mesh_terms: D002840:Chromates / Q000494:pharmacology*; D003035:Cobalt / Q000494:pharmacology*; D007477:Ions / Q000494:pharmacology; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000032:analysis*; D018384:Oxidative Stress / Q000187:drug effects; D010788:Photosynthesis; D012242:Rhodobacter sphaeroides / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002840:Chromates; D007477:Ions; D008055:Lipids; D003035:Cobalt