Evidence for a buried location of Nigeran in the cell wall of Aspergillus niger

Tung, K.K.; Nordin, John H.

doi:10.1016/0006-291x(67)90344-0

Cited by 29 publications

(15 citation statements)

References 5 publications

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“…When fraction I was incubated with a mycodextranase-containing preparation (Bull, 1970 a), reducing sugars other than glucose and P-oligoglucosides hydrolysis of the nigeran samples and 13-5 % of fraction I. Two a-linked oligoglucosides detected in nigeran digests were identified as nigerose (Glcpa~ -3Glc) and a tetrasaccharide (Glcp~1-~Glcpa1-~G1cpa-~Glc) (chromatographic criteria of Tung & Nordin, 1967). Unequivocal proof of the presence of these sugars in fraction I digests was not obtained.…”

Section: '3mentioning

confidence: 99%

Chemical Composition of Wild-type and Mutant Aspergillus nidulans Cell Walls. The Nature of Polysaccharide and Melanin Constituents

Bull

1970

Journal of General Microbiology

148

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S U M M A R YChitin and a P-linked glucan were the major chemical components of Aspergillus nidulans cell walls. Other monomeric residues identified in enzymic and acid hydrolyses of whole cell walls and cell-wall fractions included galactose, mannose, glucuronic acid and galactosamine. The P-glucan contained (I -+ 3) and ( I -+ 6) linkages and was two-thirds digested by an eX0-P-D-I ,3 glucanase prepared from a cell-wall lysing Streptomyces species. An a-glucan was identified as a cell-wall component and it also contained ( I -+ 3) linkages. This latter polysaccharide was distinguishable from nigeran (an a-1,3; a-1,4 glucan present in other Aspergillus species) by infrared spectroscopy and by its low susceptibility to hydrolysis by an endo-z-I ,3 ; a-1 ,4 glucan glucanohydrolase. Both glucans were alkali-soluble, but the P-glucan was completely solubilized only after acid extraction of the wall. The N-acetylglucosamine to galactosamine ratio in the A. nidulans cell wall was 1-32 and the two hexosamines were shown to be constituents of distinct polymers. The remaining cell wall was accounted for by protein, lipids, readily extractable and bound, and, in the wild-type, melanin.The melanin was distributed throughout the cell wall but was associated particularly with the chitin fraction. The pigment has been partially characterized chemically and contains indolic residues ; this result does not substantiate earlier views that indolic melanins are peculiar to the animal kingdom. Melanin appears to be a finite heteropolymer both in terms of its molecular size and its chemistry. I N T R O D U C T I O NA positive correlation has been demonstrated in several species between the presence of melanin, or melanin-like pigments, in the cell walls of fungi and resistance to microbial and enzymatic lysis (Potgieter & Alexander, 1966;Bloomfield &. Alexander, 1967). Furthermore, studies on Aspergillus nidulans (Kuo & Alexander., 1967) established that the resistance to lysis was affected by the melanin concentration in the cell wall. The mechanism by which melanin may exert its antilytic effect in this fungus has recently been discussed (Bull, 1g7oa).As an essential prelude to investigations of the melanin effect the cells walls of' Aspergillus nidulans were examined chemically with reference to the nature of' * (Bull & Faulkner, 1964. The two strains were distinguished by the presence and absence respectively of melanin in their cell walls. Stock cultures were maintained on a glucose-salts agar medium and 10 1. batch cultures for cell-wall preparation were grown in a liquid medium of similar composition (Carter & Bull, 1969; Bull, 197oa).Cell walls of Aspergillus nidulans I 3 . I . OL were degraded extensively by a complex of lytic enzymes synthesized by a Streptomyces species. The lytic organism was isolated from soil enriched with Phytophthora megasterium mycelium (Wang, I 964). Cultures of the streptomycete were maintained on a mineral salts agar containing 2 % (w/v) wet wt of blended Aspergillus oryzae mycelium (supplied...

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Section: '3mentioning

confidence: 99%

Chemical Composition of Wild-type and Mutant Aspergillus nidulans Cell Walls. The Nature of Polysaccharide and Melanin Constituents

Bull

1970

Journal of General Microbiology

148

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“…One carbohydrate constituent in the walls of some Aspergillus and Penicillium species (19) is the linear a-D-glucan, nigeran (15,25). This polymer is hot-water soluble, cold-water insoluble, and contains alternating 1,3 and 1,4 linkages (1).…”

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confidence: 99%

Hyphal Nigeran as a Potential Phylogenetic Marker for Aspergillus and Penicillium Species

Bobbitt

Nordin

1978

Mycologia

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“…Nigeran, a linear a-D-glucan with alternating (1--3) and (1)(2)(3)(4) linkages, is a highly crystalline matrix component of certain Aspergillus and Penicillium species (8,33). Deposition is primarily on the exterior surfaces of the hyphal walls and occurs as the nutritional sources are depleted of available nitrogen (8,18).…”

mentioning

confidence: 99%

“…Enzymatic hydrolyses with mycodextranase were carried out as previously described (8,33). Suspensions of nigeran (100 to 500 ,ug) in 0.05 M acetate buffer (pH 4.5) containing 0.1% azide were incubated overnight with 0.1 to 0.3 U (34) of purified enzyme at 40°C.…”

mentioning

confidence: 99%

Production and composition of an exocellular Nigeran-protein complex isolated from cultures of Aspergillus awamori

Bobbitt¹,

Nordin²

1982

J Bacteriol

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Evidence for a buried location of Nigeran in the cell wall of Aspergillus niger

Cited by 29 publications

References 5 publications

Chemical Composition of Wild-type and Mutant Aspergillus nidulans Cell Walls. The Nature of Polysaccharide and Melanin Constituents

Chemical Composition of Wild-type and Mutant Aspergillus nidulans Cell Walls. The Nature of Polysaccharide and Melanin Constituents

Hyphal Nigeran as a Potential Phylogenetic Marker for Aspergillus and Penicillium Species

Production and composition of an exocellular Nigeran-protein complex isolated from cultures of Aspergillus awamori

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