title: A fungus-type beta-galactofuranan in the cultivated Trebouxia photobiont of the lichen Ramalina gracilis.
abstract: A structural characterization of polysaccharides extracted from the aposymbiotically cultured photobiont of the lichen Ramalina gracilis was carried out in order to compare them with those previously found in the symbiotic thallus. The photobiont was isolated from thallus fragments, following the method of Yamamoto, and cultivated in a liquid nutrient medium. Freeze-dried cells were defatted, and the polysaccharides extracted successively with water and aq. 10% KOH, each at 100 degrees C. After purification, the soluble fractions provided a polysaccharide containing a (1-->5)-linked beta-galactofuranosyl backbone, substituted in a small proportion at O-6 by beta-Galf units. Amylose was also found, as insoluble material obtained on freeze-thawing of the alkaline extract. These polysaccharides have not been found in the symbiotic thallus of Ramalina gracilis, which contained only water-soluble (isolichenan) and insoluble glucans (nigeran and laminaran), and galactomannan. Surprisingly, the galactofuranan has similarities with those found in some fungal cell walls.
authors.affiliation: Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná-UNIOESTE, CEP 85819-110, Cascavel, PR, Brazil.
authors.forename: Lucimara M C
authors.initials: LM
authors.lastname: Cordeiro
authors.forename: Elaine R
authors.initials: ER
authors.lastname: Carbonero
authors.forename: Guilherme L
authors.initials: GL
authors.lastname: Sassaki
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Reis
authors.forename: Elfriede
authors.initials: E
authors.lastname: Stocker-Wörgötter
authors.forename: Philip A J
authors.initials: PA
authors.lastname: Gorin
authors.forename: Marcello
authors.initials: M
authors.lastname: Iacomini
mesh_terms: D000460:Chlorophyta / Q000737:chemistry* / Q000302:isolation & purification; D008011:Lichens / Q000382:microbiology*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D008970:Molecular Weight; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification; D013559:Symbiosis
chemical_list: D011134:Polysaccharides