title: Structural elucidation of the repeat unit in highly branched acidic exopolysaccharides produced by nitrogen fixing Burkholderia.
abstract: Burkholderia kururiensis, strain M130, an endophytic diazotrophic bacterium isolated from rice roots, produces acetylated acidic exopolysaccharides which can be separated by anion exchange chromatography. These were characterized by nuclear magnetic resonance spectroscopy, methylation analysis and Smith degradation. The exopolysaccharides eluted with 0.5 M NaCl were produced when the bacterium was grown in a medium containing mannitol as the sole carbon source, and showed to be a mixture of two different polymers, composed of hepta or octasaccharide repeat units, consistent with following structure: [structure: see text]. The ability of diazotrophic Burkholderia to produce two exopolysaccharides that differ by the presence of a terminal glucosyl residue provides insight into polysaccharide function with potentially significant biological consequences in the endophytic-host plant interaction.
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
authors.forename: Leticia F
authors.initials: LF
authors.lastname: Hallack
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Passos
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Mattos
authors.forename: Orlando A
authors.initials: OA
authors.lastname: Agrellos
authors.forename: Christopher
authors.initials: C
authors.lastname: Jones
authors.forename: Lucia
authors.initials: L
authors.lastname: Mendonça-Previato
authors.forename: Jose O
authors.initials: JO
authors.lastname: Previato
authors.forename: Adriane R
authors.initials: AR
authors.lastname: Todeschini
mesh_terms: D019117:Burkholderia / Q000378:metabolism*; D002240:Carbohydrate Sequence; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D009586:Nitrogen Fixation; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011135:Polysaccharides, Bacterial; D009584:Nitrogen