Open AccessStudies on neutral exopolysaccharides produced by the ectomycorrhiza Thelephora terrestris
Author(s) -
Osaku Clarice A,
Sassaki Guilherme L,
Zancan Glaci T,
Iacomini Marcello
Publication year - 2002
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2002.tb11428.x
Subject(s) - microbiology and biotechnology , chemistry , biology
The ectomycorrhizal hymenomycete Thelephora terrestris was grown in synthetic pure culture and the production of extracellular polysaccharide was monitored. The exopolysaccharides were prepared by ethanol precipitation and then fractionated into two components using a DEAE–Sepharose column. A neutral fraction (NeP) was fractionated on Sepharose CL‐6B, which resulted in three peaks: NeP1, NeP2 and NeP3. NeP1 was filtered through an exclusion membrane and two polysaccharides were obtained (fractions: NeA, NeB). Fraction NeB was submitted to methylated derivatives and 1 H‐, 13 C‐ and 2D NMR spectroscopic analyses. These analyses showed a main chain of a (1→6)‐linked α‐ d ‐Man p units substituted at O ‐2 by a variety of side chains containing α‐Fuc p , β‐Xyl p and β‐Gal p residues. The main fraction corresponds to mannan as shown by methylation analysis. Size exclusion chromatography (HPSEC‐MALLS) of fraction NeB showed a main component of 15.0 kDa. It contained mannose, galactose, fucose and xylose in a molar ratio of 50:29:11:10. The fractions NeP2 and NeP3 were characterised as a (1→6)‐linked β‐glucan (pustulan) and (1→3)‐linked β‐glucan, respectively.