Galactomannans from the cell walls of species of Paecilomyces sect. Paecilomyces and their teleomorphs as immunotaxonomic markers

Abstract

An alkali-extractable and water-soluble fraction (F1S) was obtained from cell walls of Paecilomyces variotii and species of the related genera Talaromyces, Byssochlamys and Thermoascus. The structure of the main polysaccharide of these fractions was studied and found to consist of a core of (1 6)-α-mannopyranose partially substituted at O-2 by chains of galactofuranose and shorter chains of mannopyranose. The differences in the regularity of the branching points and the length of the galactofuranose side chains are useful to distinguish between species. These differences were detected by immunological methods, since highly specific polyclonal antibodies were raised against these polysaccharides. Mycelium of P. variotii CBS 990.73A was stained by indirect immunofluorescence. The polysaccharides studied in this work differ from the one described for species from section Isarioidea, and this is another indication of the heterogeneity of the genus Paecilomyces.

Evaluation of Exopolysaccharide Production by Leuconostoc mesenteroides Strains Isolated from Wine

“…Then, to determine their composition, the EPSs were subjected to 2 different hydrolytic conditions. To release the fructofuranose residues, 0.15 M TFA was used, but these soft conditions do not hydrolyze the more resistant linkages of pyranoses (Domenech and others 1999; Politi and others 2006). To release nonfuranosidic components, 3 M TFA was necessary, but leads to the destruction of fructose and other furanoses (Domenech and others 1999; Politi and others 2006; Prieto and others 2007).…”

Features and functions of covalently linked proteins in fungal cell walls

“…Unfortunately, in many cases the data have been obtained using cell wall fractions such as galactomannan isolated by relatively harsh extraction methods without any attempt to determine if this material might represent protein-bound N-chains or perhaps otherwise (Ahrazem et al, 2002a,b;Domenech et al, 1999;Nakajima et al, 1984b). This has become especially relevant since the identiWcation of a galactomannan in A. fumigatus cell walls directly linked to the 1,3--glucan network (Fontaine et al, 2000).…”

An assessment of fungal wall heteromannans as a phylogenetically informative character in ascomycetes

“…1) and its structure can be determined. The α‐mannan cores from some of the polysaccharides investigated have been studied, and they display fairly similar structures, always containing a main chain of α‐(1→6)‐ d ‐mannose units more or less substituted by α‐mannose side chains (Prieto et al , 1997, 2001, 2002; Leal & Bernabé, 1998; Ahrazem et al , 1999, 2000a, b, 2003a; Domenech et al , 1999, 2002; Pereyra et al , 2003; Gómez‐Miranda et al , 2004). They resemble those described for some mannans from yeast mannoproteins (Fleet, 1991), which could suggest that they are a relic of the ancestral wall polysaccharide of the Ascomycota .…”