title: Capillary electrophoresis-mass spectrometry of citrus endophytic bacteria siderophores.
abstract: CE-ESI-MS with a liquid sheath interface and IT mass analyzer was used for analysis of siderophores from different strains of Methylobacterium spp. citrus endophyte extracts. Three Methylobacterium strains were investigated according to positive bioassay tests. Bacteria cultures were grown under Fe(III) absence (siderophore producing cultures) and under Fe(III) presence (control cultures). Siderophores were extracted from culture supernatant with polystyrene resins. BGE and sheath-liquid composition were optimized, respectively, in order to assure both, best peak resolution and ESI-MS sensitivity. The best analysis conditions were obtained with 100 mmol/L ammonium bicarbonate at pH 8 as BGE and methanol:H(2)O 25:75 + 0.05% formic acid as sheath liquid. CZE-ESI-MS analysis revealed two possible siderophores, according to bacterium species, presenting M(r) of 1004.3 and 798.3 Da.
authors.affiliation: Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, Brazil.
authors.forename: Ana V Colnaghi
authors.initials: AV
authors.lastname: Simionato
authors.forename: Carolina
authors.initials: C
authors.lastname: Simó
authors.forename: Alejandro
authors.initials: A
authors.lastname: Cifuentes
authors.forename: Paulo Teixeira
authors.initials: PT
authors.lastname: Lacava
authors.forename: Wellington Luiz
authors.initials: WL
authors.lastname: Araújo
authors.forename: João Lúcio
authors.initials: JL
authors.lastname: Azevedo
authors.forename: Emanuel
authors.initials: E
authors.lastname: Carrilho
mesh_terms: D001639:Bicarbonates / Q000378:metabolism; D002957:Citrus / Q000382:microbiology*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005561:Formates / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism; D000432:Methanol / Q000737:chemistry; D020580:Methylobacterium / Q000254:growth & development / Q000378:metabolism*; D017262:Siderophores / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D001639:Bicarbonates; D005561:Formates; D017262:Siderophores; D014867:Water; C030544:formic acid; C027043:ammonium bicarbonate; D007501:Iron; D000432:Methanol