Extracellular Fungal Polysaccharides

Extracellular Fungal Polysaccharides.—Neither of the two polysaccharides associated with the acid protease from Aspergillus oryzae is bound to the protein by a covalent linkage, although they may stabilize the protease during secretion.  

Hirose, T. Kiho, and C. Hara, Chem. and Pharm. Bull. (Japan), 1977, 25, 338. 

FrensdorfT, and E. Galun, Arch. MikrobioL, 1976. 108, 9. 

Fujimoto, A. Kuninaka, and H. Yoshino, Agric. and Biol. Chem. (Japan), 1977, 41, 1111. 

Although the presence of tartrate in the growth medium did not affect the synthesis of an extracellular polymer containing 2-acetamido-2-deoxy-D-galacto-pyranosyl residues by A. parasiticus, the acetyl content of the polymer decreased, due, possibly, to the production of an acetylase. Treatment of Aureobasidium pullulans with ethidium bromide produced several mutant strains, which, on culturing, formed a high proportion of yeast-like cells. Comparison of several mutant strains with the wild-type strain suggested that the yeast-like cells are responsible for the synthesis of pullulan. 

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Other polysaccharides whose solutions yield liquid crystalline phases include the bacterial polysaccharide xylan and the extracellular fungal polysaccharide produced by schizophyllum commune... 

Extracellular fungal polysaccharides are also produced by some fungi( ), however, very little information is available about the crystal structure of that class of polysaccharides 6). 

Microbial and Fungal Polysaccharides. Last but not least, we may consider (very superficially) the family of the microbial polysaccharides, in particular the extracellular microbial carbohydrate polymers (Sandford, 1979). The number of microbial species which can produce substantial amounts of different polysaccharides is large. Moreover the degree of polymer production by a given orga-... 

Similar considerations apply to the so called Fungal Polysaccharides (see Marchessault and Deslandes, 1980). An incomplete list of such polysaccharides is given in Table 6. Among extracellular gums which have met the greatest commercial success one should recall xanthan, the repeating unit of which is depicted in Fig. 

Of special interest are the polysaccharides that act as elicitors. Various heterogeneous polymers obtained from fungal and bacterial cell walls also act as elicitors. These include extracellular polysaccharides, lipoprotein polysaccharides, and glycoproteins. 

In addition to the cell wall and a possible capsule as primary and secondary protective layers, respectively, some fungal cells have developed mechanisms for the production of extracellular polysaccharides (EPS) similarly to the capsule, the EPS forms a complex matrix used as a protective barrier when the cells are subjected to specific environmental or stressful constraints (such as salt or pH stress). But, contrary to the... 

Wouters, 1., Spaan, S., Douwes, J. Doekes, G. Heederik, D. 2006. Overview of personal occupational exposure levels to inhalable dust, endotoxin, beta (l-->3)-glucan and fungal extracellular polysaccharides in the waste management chain. Ann Occup Hyg 50(1) 39-53. 

Jacobs and Ahmadjian (1969), who examined the ultrastructure of ten foliose and fruticose nongelatinous lichens, found a thick (up to 1 /urn) fibrillar material of a polysaccharide nature surrounding the fungal cell wall. A similar extracellular polysaccharide was also found between the cells of the Trebouxia phycobiont. This substance supposedly facilitates the water retention ability of the thallus. 

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