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Extracellular mannans

The initial studies carried out on the biosynthesis of yeast wall were directed towards learning the mechanisms of sugar polymerization in vivo, Bretthauer et fed Han-senula holstii cells with radioactive glucose or mannose and found that the extracellular mannan was produced from either sugar. [Pg.189]

Several methylated sugars have been identified in hydrolyzates of LPS, cell-wall polysaccharides, and extracellular polysaccharides. A considerable number of these have been found in the LPS from photosynthetic prokaryotes. Two polysaccharides from Mycobacterium species, a glucan" and a mannan" are remarkable in that they contain high percentages of methylated sugars. Glycolipids from Mycobacterium species are also rich in methylated sugars, some of which have not been found elsewhere, but this is beyond the scope of the present article. [Pg.300]

There is no information so far available about mannan degrading enzymes of alkaliphiles. In this paper, a P-mannan degrading alkaliphile Bacillus sp. AM-001) with high productivities of cell-associated P-mannosidase and three extracellular P-... [Pg.52]

The mycobacterial cell wall contains the essential lipoglycan structures lipoarabinomannan, lipomannan, and phosphatidyl-my6>-inositol-mannosides (PIMs) [262]. These molecules are attached to the cytoplasmic membrane and extend through the cell wall into the extracellular environment (O Fig. 1). PIMs, LMs, and LAMs are attached to the cytoplasmic membrane by a conserved anchor, which consists of an sn-glycero-3-phospho-(l-D-my6>-inositol), with a single cx-D-Man/> linked at C2 of the my6>-inositol (O Fig. 19c). The mannan core is attached to C6 of the my6>-inositol unit. There are four potential sites of fatty acid attachment on the anchor both free hydroxyls of the glycerol unit, C6 of the Man/ linked to C2 of my6>-inositol and C3 of the my6>-inositol. The fatty acids are most commonly palmitic and tuberculostearic (10-methyl-octadecanoic) acids, and less frequently, stearic acid. Other fatty acids are seen in... [Pg.1574]

Methyl ethers of Man, mono-substituted at the 2, 3, 4 or 6 positions have been reported in the lipopolysaccharides of photosynthetic procaryotes [82, 83]. The reducing end of the mannans from Mycobacterium smegmatis and Streptomyces griseus have a terminal a-O-methyl group on C-l and Man30Me in the polymer chain. The lactic acid ether 4-0-[-(S)-l- carboxyethyl]-D-mannose is a component of extracellular polysaccharides of Mycobacterium spp., and a-amino-3-0-[-... [Pg.1123]

The extracellular enzymes of yeast are glycoproteins and include invertase and acid phosphatase. Strains of Saccharomyces carlsbergensis but not S, cerevisiae also possess melibiase. Yeast invertase has a minimum molecular weight of 27 000 contains 50 % mannan and 2-3 % glucosamine [43]. The precise location of the extracellular enzymes is still uncertain. They may occupy the space (periplasm) between the membrane and the bulk of the wall components, be anchored to the membrane via protein or covalently associated with other mannan or even glucan molecules. [Pg.162]

Various strains of yeasts that produce characteristic phosphono-D-mannans also synthesize characteristic extracellular a-D-mannans, which appear to differ in the degree of branching and in the type of glycosidic linkages. Methylation analysis showed that the mannans contain a fl 6)-linked a-D-mannosyl backbone, to which (1 3)-linked [e.g. (19) in Pichia mucosa] or (1 3)- and/or... [Pg.272]

Yeasts produce a number of emulsifiers, which are particularly interesting because of the food grade status of several yeasts. Liposan is an extracellular emulsifier produced by Candida lipolytica (Cirigliano and Carman 1984). It is composed of 83 % carbohydrate and 17 % protein. Mannan-protein emulsifiers are produced by Saccharomyces cerevisiae (Cameron et al. 1988). A variety of polymeric bioemulsifiers for potential use in foods was studied by Shepherd et al. 1995. [Pg.287]

Schizomycophyta Myxomycopkyta EumycophyUt (bacteria, molds, and fungi) chitin cellulose mannans starches levans glycogen extracellular polysaccharides... [Pg.186]


See other pages where Extracellular mannans is mentioned: [Pg.40]    [Pg.40]    [Pg.116]    [Pg.178]    [Pg.350]    [Pg.2457]    [Pg.326]    [Pg.41]    [Pg.1128]    [Pg.110]    [Pg.53]    [Pg.283]    [Pg.309]    [Pg.309]    [Pg.310]    [Pg.468]    [Pg.113]    [Pg.310]    [Pg.127]    [Pg.240]    [Pg.19]    [Pg.61]    [Pg.607]    [Pg.274]    [Pg.1610]    [Pg.1778]   
See also in sourсe #XX -- [ Pg.40 , Pg.41 , Pg.42 , Pg.43 ]




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