Taxonomic Specificity of the Sensitivity to the Wickerhamomyces bovis Fungistatic Mycocin.

Wickerhamomyces bovis type strain was found to secret a mycocin with a fungistatic effect at pH from 3.5 to 6.0.

[Antifungal Activity of Wickerhamomyces silvicola].

Wickerhamomyces silvicola strain Y-178 was shown to secrete a mycocin with a fungicidal effect. It exhibits the highest activity at pH 4.5 and elevated ambient osmotic pressure.

[Intraspecific and Intrageneric Antagonistic Activity of Wickerhamomyces anomalus].

A total of 53 Wickerhamomyces anomalus strains were examined for antagonistic activity, including the nomenclature types of the species with the names presently considered synonymous. Over 70% of the strains exhibited antibiotic activity. According to the action spectra of intraspecific activity, the strains fell into three groups, while according to their activity against other Wickerhamomyces species and phylogenetically related Candida species they formed five subgroups.

Characterization of two different toxins of Wickerhamomyces anomalus (Pichia anomala) VKM Y-159.

Wickerhamomyces anomalus VKM Y-159 strain produces two types of toxin designated as WAKT a and WAKT b, encoded by chromosomal genes. The WAKT a toxin is heat-labile, pronase sensitive acting in pH range 3-4 affecting on several yeasts including pathogenic Candida species while the WAKT b toxin is protease- and thermo-resistant, acting in pH range 3-7 on two species, Candida alai and Candida norvegica. The rapid decrease of the number of viable cells after toxin treatment demonstrates that both toxins have cytocidic effect.

Ultrastructural characteristics and variability of vegetative reproduction in Fellomyces penicillatus.

The yeast strains VKM Y-2977 and VKM Y-2978, derived from the isolate Pa-202, were examined for their physiological properties and mycocin sensitivities and studied by light, phase-contrast, fluorescence, transmission and scanning electron microscopy. The cells of the first strain produced long stalk-like conidiophores, whereas the cells of the second one had the appearance of a typical budding yeast under the light microscope. Transmission and scanning electron microscopy showed the formation of stalk-like conidiophores and long necks in VKM Y-2977, similar in appearance to Fellomyces fuzhouensis.