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Biomedical subjects

N V Golubev

Publications and source records attributed to N V Golubev.

4 recordsLinked to original sources

[Selenium tolerance of yeasts].

Selenium tolerance of yeasts widely varies: the growth of some yeasts can be inhibited by a selenium concentration as low as 10(-4) M, whereas others can grow in the presence of 10(-1) M selenium. Homogeneous yeast taxa are characterized by a certain level of selenium tolerance, and heterogeneous taxa show a variable level of tolerance to selenium. In general, ascomycetous yeasts are more tolerant to selenium than basidiomycetous yeasts. Among the ascomycetous yeasts, the genera Dekkera and Schizosaccharomyces exhibited the lowest and the species Candida maltosa, Hanseniaspora valbyensis, Kluyveromyces marxianus, and Yarrowia lipolytica the highest tolerance to selenium. Among the basidiomycetous yeasts, the genera Bullera, Cryptococcus, and Holtermannia showed the lowest and the species Cryptococcus curvatus, Cr. humicola, and Trichosporon spp. the highest tolerance to selenium. The selenium tolerance of yeasts depends on the composition of the growth medium, in particular, on the presence of sulfate, sulfur-containing amino acids, and glutamine in the medium.

Adaptation, Physiological↗

[A new basidiomycetous yeast species, Cryptococcus mycelialis, related to Holtermannia Saccardo et Traverso].

A new species of the genus Cryptococcus, Cr. mycelialis (the type strain VKM Y-2863), is described based on the taxonomic study of four strains isolated from the soil and plant samples collected on the South Georgia and East Falkland islands. This species differs from the known Cryptococcus species in its ability to form a true monokaryotic mycelium with pseudoclamp connections and haustoria. The species can be distinguished from the phylogenetically related and phenotypically similar species Holtermannia corniformis and Cr. nyarrowii by some assimilatory reactions, maximum growth temperature, and sensitivity to mycocins.

Atlantic Islands↗

[Selection and study of potent lactose-fermenting yeasts].

Whey-fermenting Kluyveromyces cultures were revealed among 105 yeast strains assimilating lactose. Eighteen most potent strains isolated from milk products fermented galactose, sucrose, and raffinose, in addition to lactose. Many yeast strains fermented inulin. Most strains were resistant to cycloheximide and grew in medium containing glucose, NaCl, and ethanol at concentrations of up to 50, 11-12, and 10-12%, respectively (4 degrees C). Three strains had mycocinogenic activity. After fermentation of whey with selected yeast strains at 30 degrees C for 2-3 days, ethanol concentration was 4-5%.

Culture Media↗

[The fungicidal activity of an extracellular glycolipid from Sympodiomycopsis paphiopedili sugiyama et al].

The yeast Sympodiomycopsis paphiopedili (Ustilaginomycetes) produces an extracellular glycolipid, which possesses the maximum antifungal activity at the pH of the medium equal to 4.0-4.5. Among the approximately 300 tested species of yeastlike and mycelial fungi, more than 80% (including species pathogenic for plants, animals, and humans) were found to be susceptible to this glycolipid.

Antifungal Agents↗