Taxonomic group: fungi / Ascomycota
(Phylum: Ascomycota)
Organ / tissue: thallus
The structure was elucidated in this paperPublication DOI: 10.1111/j.1574-6968.2004.tb09740.xJournal NLM ID: 7705721Publisher: Blackwell Publishing
Correspondence: iacomini
bio.ufpr.br
Institutions: Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19.046, CEP 81.531-990, Curitiba, PR, Brazil, Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná - UNIOESTE, CEP 85819-110, Cascavel, PR, Brazil, Institute of Plant Physiology, University of Salzburg, Hellbrunner Str. 34, A-5020 Salzburg, Austria
A structural elucidation of polysaccharides extracted from the aposymbiotically cultured mycobiont of the lichen Ramalina peruviana was carried out in order to determine whether the polysaccharides found previously in the symbiotic thalli are produced by the mycobiont or photobiont or both. The mycobiont isolate was cultivated on a solid malt-yeast extract-medium and the freeze-dried colonies were detailed and the polysaccharides extracted successively with hot water and aq. 2% KOH, each at 100 degreesC. The alkaline extract was obtained in much higher yield (31.5%) and submitted to a freeze-thawing treatment, giving rise to a precipitate (PK2) of a mixture of (1→3),(1→4)-α-glucan (1.2:1 ratio, nigeran) and a (1→3)-β-glucan (laminaran). The mother liquor was treated with Fehling solution to give a precipitate (galactomannan). This had a (1→6)-linked α-D-mannopyranosyl main chain, substituted at O-4 and in small proportion at O-2,4 by β-Galp units. All three polysaccharides have previously been found in the symbiotic thalli of R. peruviana, showing that these are produced by the fungus, without the participation of the Trebouxia photobiont. Surprisingly, isolichenan, a cold-water soluble (1→3),(1→4)-α-linked-glucan (3:1 ratio) was not found in the isolated mycobiont, despite being the main polysaccharide found in the thalli.
polysaccharides, Galactomannan, lichen, Ramalina peruviana, cultured mycobiont, alpha- and beta-glucans, α- and β-Glucans
Structure type: homopolymer
Location inside paper: abstract, p.82, structure 1A
Trivial name: LAM, mannan, galactomannan, cell wall heteromannan
Compound class: EPS, O-polysaccharide, cell wall polysaccharide, N-glycan, cell surface polysaccharide, mannan, D-mannan, galactomannan
Contained glycoepitopes: IEDB_130701,IEDB_140116,IEDB_141793,IEDB_141828,IEDB_144983,IEDB_152206,IEDB_153220,IEDB_153762,IEDB_153763,IEDB_76933,IEDB_983930,SB_198,SB_44,SB_67,SB_72
Methods: 13C NMR, 1H NMR, methylation, GC-MS, acid hydrolysis, GLC, composition analysis, HPSEC-MALLS, acetylation, alkaline extraction
Comments, role: The methylation data are consistent with the presence of a (1->6)-linked a-mannopyranosyl backbone mainly substituted at O-4 and in small proportion at O-2,4 by b-Galp units.
Related record ID(s): 41297, 41298, 41300, 41301
NCBI Taxonomy refs (TaxIDs): 475428Reference(s) to other database(s): GTC:G55317BB, GlycomeDB:
6776, CCSD:
46066, CBank-STR:6345
Show glycosyltransferases
There is only one chemically distinct structure:
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