Short and thick fibers were observed on the outer surface of the yeast phase of Paracoccidioides brasiliensis, and long and thin fibers were seen on the inner surface The long fibers disappear with chitinase treatment and are composed of chitin The short fibers disappear under alkali treatment and are composed of α-glucan Comparisons with α-(1 → 3)-glucan isolated from Aspergillus niger and Polyporus betulinus and with chitin from fungal origin support our point of view

Chemical morphology of glucan and chitin in the cell wall of the yeast phase of Paracoccidioides brasiliensis.

The myxomycete, Physarum polycephalum, can be induced under laboratory conditions to form two different hard-walled forms, spores and spherules. Characterization of both types of walls revealed only a single sugar, galactosamine. It was identified after acid hydrolysis of the isolated walls by chromatography in three solvent systems, by its positive reaction with ammoniacal silver nitrate, ninhydrin, Galactostat, and the Elson-Morgan test, and by ninhydrin degradation to lyxose. Galactosamine was present as a polymer with solubility characteristics the same as the β1-4–linked glucosamine polymer (chitosan). The walls were also found to contain about 2% protein. Spherule walls revealed a single glycoprotein on gel electrophoresis. Spore walls contained a similar protein component. The phosphate content of isolated spherule walls was 9.8%, and that of spore walls was 1.4%. Spore walls also contained about 15% melanin which was shown to be similar to fungal melanin. A novel method was used to measure the rate of mature spherule formation based on the loss of extractability of P. polycephalum natural pigment. The presence of a rare galactosamine polymer in P. polycephalum spore and spherule walls as the only carbohydrate suggests that the myxomycetes are not closely related to the fungi or the protozoa.

Isolation and Characterization of a Galactosamine Wall from Spores and Spherules of Physarum polycephalum

Differences in the cell wall composition in the type species ofEupenicillium andTalaromyces

Chemical and ultrastructural studies of isolated cell walls of Epidermophyton floccosum: Presence of chitin inferred from X-ray diffraction analysis and electron microscopy

Mycelial cell wall of Aspergillus oryzae M-13 grown in an α-amylase-forming medium could not bind α-amylase (Taka-amylase A, EC 3211) However, by treatment with 10 n NaOH at 100 C for 30 min, the wall gained the ability to bind α-amylase This phenomenon was caused by removal of a factor (designated as masking factor) which masked the binding site for α-amylase The masking factor was purified as a preparation giving a single peak in both ultracentrifugation (16 S ) and by gel electrophoresis ( M BPB , 10) Approximately 20 μg of the purified factor, bound to 10 mg of the alkali-treated mycelial cell wall, prevented the binding of approximately 100 μg of α-amylase or released approximately 100 μg of α-amylase which previously was bound to the alkali-treated wall These findings indicate that the factor has much higher affinity than α-amylase for the binding site on the mycelial wall The masking factor was inducibly formed accompanying the secretion of α-amylase Images

Presence of Binding Site for α-Amylase and of Masking Protein for This Site on Mycelial Cell Wall of Aspergillus oryzae

It has been suggested (P. W. Brian, Trans. Brit. Mycol. Soc. 43:1, 1960) that the antibiotic griseofulvin affects only those fungi possessing chitin in their cell wall, but there is a growing body of evidence which makes it unlikely that the presence of chitin is the sole prerequisite for the action of the antibiotic. For instance, K. J. Bent and R. H. Moore (Biochemical Studies of Anti-microbial Drugs, Cambridge Univ. Press, London, 1966) reported that the chitin content of whole mycelia of Botrytis allii increased after griseofulvin treatment rather than decreased, and D. E. Eveleigh and S. G. Knight (Bacteriol. Proc., p. 27, 1965) found that the glucosamine-toglucose ratio of the cell wall of Trichophyton mentagrophytes is unchanged by griseofulvin. This communication reports the presence of chitin in the cell wall of Penicillium patulum, when it was grown under conditions which permitted the production of griseofulvin. P. patulum was obtained through the courtesy of R. S. C. Aytoun of Glaxo Research Ltd., Buckinghamshire, England. It was grown in surface culture in a fully synthetic medium (D. A. Applegarth, Arch. Biochem. Biophys. 120:471, 1967). The medium was supplemented by the addition of sodium chloride (0.2 g/liter) to provide the chlorine atoms of the griseofulvin molecule. The mycelial pads were harvested after 7 days, and the contents of one of the flasks was dried and analyzed for griseofulvin according to the method of A. Holbrook, F. Bailey, and G. M. Bailey (J. Pharm. Pharmacol. 15(Suppl.): 270, 1963). The 7-day mycelial growth from each liter of solution contained approximately 8 mg of griseofulvin. Cell walls were prepared from the mycelial pads in the remaining flasks by ballistic disruption of the hyphae with glass beads in a Sorvall Omnimixer (D. A. Applegarth, Arch. Biochem. Biophys. 120:471, 1967). The purified cell walls contained 12.3% glucosamine and a trace of galactosamine (approximately 0.5%). The hexosamines were eluted from Whatman 3MM paper developed with n-butanolacetic acid-water (4:1:5, v/v). Their identity was established by co-chromatography, with authentic standards, in three solvent systems; by ninhydrin oxidation (P. J. Stoffyn and R. W. Jeanloz, Arch. Biochem. Biophys. 52:373, 1954); and by Nacetylation followed by chromatography in three solvent systems. The identity of the glucosamine polymer as chitin was established as follows. Cell walls (10 mg) were extracted with 1 N acetic acid (5 ml) at 100 C for 20 min. The acid extract was removed by centrifugation, and Gram's iodine solution was added to the extract. No color was obtained. This suggested that the walls did not contain chitosan. The residual walls

G Bozoian

Papers

Presence of chitin in the cell wall of a griseofulvin-producing species of penicillium.