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V Musílek

Publications and source records attributed to V Musílek.

At least 19 recordsLinked to original sources
PubMed1989

Flavovirin--a new antifungal antibiotic produced by the pyrenomycete Melanconis flavovirens.

The pyrenomycete Melanconis flavovirens was found to produce a mixture of two antifungal antibiotics. The first has been already described; the antibiotic is identical with thermozymocidin (myriocin). The second antibiotic is a new compound, whose isolation and identification is presented in this paper. The chemical structure of this substance (C21H37NO5) was determined to be 2-amino-2-hydroxymethyl-3,4-trans-epoxy-14-oxo-eicos-trans-6-enoic acid. After the producer it was named flavovirin and it possesses strong activity against yeasts and a moderate effectivity against filamentous fungi.

Amino Acids↗
PubMed1989

Production of thermozymocidin (myriocin) by the pyrenomycete Melanconis flavovirens.

Submerged culture of the pyrenomycete Melanconis flavovirens produces a strongly active antifungal antibiotic. The antibiotic was isolated from the culture mash. In purified compound the physico-chemical characteristics, including 1H NMR spectrum, were estimated. The antibiotic was found to be identical with thermozymocidin (myriocin) as confirmed by comparison with synthetically prepared thermozymocidin.

Amino Alcohols↗
PubMed1985

Glucose-2-oxidase activity in mycelial cultures of basidiomycetes.

The activity of intracellular glucose-2-oxidase was tested in 40 species of 26 basidiomycete genera. The enzyme catalyzing the oxidation of D-glucose to the dicarbonyl sugar D-arabino-2-hexosulose was demonstrated in mycelial extracts of 9 species of Aphyllophorales and 6 species of Agaricales cultivated in liquid media. In the majority of species exhibiting this activity hexosulose was detected in the cultivation medium. The highest enzyme activity was detected in Oudemansiella mucida, Coriolopsis occidentalis, Fomes fomentarius, Trametes versicolor and a not-yet-classified species of the genus Trametes.

Basidiomycota↗
PubMed1982

Metabolism of aromatic acids in the antibiotic-producing basidiomycete Oudemansiella mucida.

Aromatic acids were determined in the mycelium and fermentation medium of Oudemansiella mucida. Coumaric acids (both m- and p-), p-hydroxybenzoic acid (salicylic acid) and benzoic acid were found to predominate in the mycelium. Phenylacetic acid represents the main component in the medium. Phenylalanine ammonia-lyase catalyzing conversion of phenylalanine to cinnamic acid which is further metabolized to benzoic acid was detected in the mycelium. The results are discussed with respect to the synthesis of the antibiotic mucidin.

Alkenes↗
PubMed1982

Effect of tryptophan on the production of mucidin in cultures of basidiomycete Oudemansiella mucida.

Addition of L-tryptophan to cultures of the basidiomycete Oudemansiella mucida brought about a pronounced increase of production of the antibiotic mucidin. The highest increase was reached in the presence of 0.15-0.20% tryptophan and after its addition to a l-d culture. The methyl ester of tryptophan exhibited the same effect. Mycelium growing during the initial phases in the presence of tryptophan synthesized mucidin powerfully during later phases of the fermentation.

Alkenes↗
PubMed1982

Effect of glucitol on the production of mucidin in Oudemansiella mucida.

When studying the biosynthesis of mucidin under production (glucose as the main carbon source) and non-production (glucitol as the main carbon source) conditions it could be shown that the producer, Oudemansiella mucida, utilizes glucitol both for growth and for mucidin biosynthesis. However, the production of mucidin is 10 times lower than on glucose. When the culture was preincubated on glucose and transferred to non-production conditions the negative effect of glucitol could not be demonstrated. Biosynthesis of mucidin is influenced by the used carbon source already at an early stage of the cultivation.

Agaricales↗
PubMed1981

Mucidin-nonproducing mutants of oudemansiella mucida.

Mutants of Oudemansiella mucida, blocked in the biosynthesis of the antibiotic mucidin, were obtained at a 0.28% frequency after the application of N-methyl-N'-nitro-N-nitrosoguanidine (MNG) to basidiospores under conditions leading to 0.5--5.0% survival rates. Loss of antibiotic activity was in most isolates accompanied by a decrease in mycelium growth rate and a suppression of dikaryotizing and fructification ability. Recombination analysis of two stable mutants revealed that the block in mucidin synthesis is the result of mutation in the same chromosomal gene (muc). In contrast to the action of MNG, UV-irradiation leads neither to the loss of biosynthetic activity nor to any morphological change.

Agaricales↗
PubMed1978

Biosynthesis of fatty acids and sterols in relation to the antibiotic formation in Oudemansiella mucida.

The production of mucidin by the basidiomycete Oudemansiella mucida was negatively influenced by the application of D-glucitol as the main carbon source, the effect being independent of the growth rate of the mycelium. The rate of fatty acid synthesis was measured by incorporation of 1-14C-acetate. After 8 days of cultivation, the amount of fatty acids was approximately half that synthetized during cultivation on glucose. The specific rate of incorporation reached its maximum after seven days of cultivation. Incorporation of 2-14C-MEValonate into sterols was the same under the two sets of cultivation conditions. Acetate units from the degraded fatty acids are probably also utilized for antibiotic synthesis.

Acetates↗
PubMed1978

Glucose-2-oxidase activity and accumulation of D-arabino-2-hexosulose in cultures of the basidiomycete Oudemansiella mucida.

Submerged cultures of the basidiomycete Oudemansiella mucida, strain III, accumulate D-arabino-2-hexosulose. The maximum yields during cultivations in shaker flasks or in a laboratory fermentor are 6--12 and 15 mg/ml, respectively (20--50% conversion of substrate glucose). The accumulation is transient, the aldoketose being again utilized after glucose exhaustion. Its production is stimulated by fluoride ions. The enzyme responsible for the C(2)-specific oxidation of D-glucose acts as an intracellular oxidase with a maximum activity in the exponential phase of growth. D-arabino-2-Hexosulose was also detected in the cultivation medium of the wood-rotting fungi Pleurotus ostreatus, Laetiporus sulphureus, and Phellinus abietis.

Basidiomycota↗
PubMed1978

Soluble sugars in the mycelium of the basidiomycete Oudemansiella mucida.

Quantitative gas chromatography was used to determine soluble neutral sugars in an extract of the fungus Oudemansiella mucida grown on a synthetic glucose medium. Apart from the usual fungal sugar components, viz. trehalose, D-glucose, D-mannitol, D-arabinitol, glycerol and inositol, the 6-day-old mycelium contained D-arabino-2-hexosulose (D-glucosone). In the period of maximum growth, this aldoketose was the predominant monosaccharide (3.4% mycelial dry weight).

Basidiomycota↗
PubMed1977

alpha-Mannosidase and mannanase of some wood-rotting fungi.

Cultivation media from 11 wood-rotting fungi contained alpha-mannosidase and mannanase activity, alpha-Mannosidase was studied in more detail in Phellinus abietis and mannanase was studied more intimately in basidiomycetes Phellinus abietis, Trametes sanguinea and Pholiota aurivella. Suitable cultivation conditions and optimum conditions for the production of alpha-mannosidase and mannanase were determined. Both enzymes are constitutive; mannanase is extracellular, alpha-mannosidase was found in both mycelium and cultivation medium.

Basidiomycota↗
PubMed1977

Antifungal antibiotic of the Basidiomycete Oudemansiella mucida. II. Life cycle and fructification of the producing fungus.

The developmental cycle of the fungus Oudemansiella mucida, the producer of a new antifungal antibiotic, was found to be controlled by the mechanism of homogenic tetrapolar incompatibility; under our conditions, the cycle took about 12 weeks to completion. Optimum conditions for a laboratory-scale fructification were investigated. Normal fruiting body formation required sufficient illumination, temperatures below 20 degrees C, and relative humidity in excess of 70%. Flask-grown fruiting bodies did not differ from the naturally occurring ones. The basidiospores of the produced fruiting bodies yielded the reference monokaryons necessary for physiological, cytological and genetical studies.

Antifungal Agents↗
PubMed1977

Antifungal antibiotic of the Basidiomycete Oudemansiella mucida. III. Nuclei in the hyphae of mono- and dikaryons.

Nuclear ratios were studied in terminal and subterminal cells of various mycelia of the basidiomycete Oudemansiella mucida, the producer of the antifungal antibiotic mucidin (MuciderminR Spofa). The dikaryon, the monokaryon, and the mucidin-producing strain that had been cultivated for a long time under submerged conditions were compared. Dedikaryotization was found to have taken place in the producing strain. The originally dikaryotic culture with characteristic clamp connections on the mycelium and with two nuclei in every hyphal cell lost permanently the clamp connections, probably owing to continuous intense agitation. The hyphae contained solely mononuclear cells. Mating with a compatible monokaryon yielded a dikaryon capable of normal fructification.

Antifungal Agents↗
PubMed1977

Separation and properties of alpha-mannosidase and mannanase from the basidiomycete Phellinus abietis.

Proteins of a crude enzyme preparation obtained from the cultivation medium of the basidiomycete Phellinus abietis were separated by gel filtration and ion-exchange chromatography. The preparation contained a minimum of three enzymes capable of splitting alpha-D-mannosidic bonds: alpha-mannosidase, exomannanase, and endomannanase, which were separated. Some properties of the mannanase complex of the crude enzyme preparation, and of a partially purified alpha-mannosidase were examined. The mannanase complex exhibited two pH optima, its temperature optimum being at 45 degrees C. The pH optimum of purified alpha-mannosidase was at pH 5.0, the temperature optimum being at 45 degrees C. The pH optimum of purifed alpha-mannosidase was at pH 5.0, the temperature optimum at at 60 degrees C; the enzyme had a relatively high heat stability. The Km of alpha-mannosidase for p-nitrophenyl alpha-D-mannopyranoside was 1.5 X 10(-5) M. Pure alpha-mannosidase did not split mannan.

Basidiomycota↗
PubMed1975

Lipids in fruiting bodies of the basidiomycete Oudemansiella mucida.

Dried fruiting bodies of the basidiomycete Oudemansiella mucida contain 29.1% total lipids. Their qualitative analysis revealed the presence of mono-, di-, triglycerides, sterols, free fatty acids and sterolesters. Quantitatively most significant were triglycerides (37.9%) and free fatty acids (29.7%). The phospholipid fraction contained phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidic acid. Gas chromatography showed the presence of a broad spectrum of fatty acids. The ratio between the neutral and polar fractions was 6 : 1, both having linoleic acid as the main component.

Anti-Bacterial Agents↗