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Acta Botanica Hungarica
Authors: T. O. Kondratiuk, S. Y. Kondratyuk, M. V. Khimich, T. V. Beregova, and L. I. Ostapchenko

Status of black melanin-containing yeast-like fungus Exophiala alcalophila isolated from microorganism complex of hermetic damaged in conditions of indoor high humidity in Kiev, Ukraine is proved by combined phylogenetic analysis based on sequences of the internal transcribed spacer 1 (ITS1), the 5.8S gene and the internal transcribed spacer 2 (ITS2) nrDNA, beta-tubulin gene and translation elongation factor 1-alpha gene. Sequences of the mentioned genes of Ukrainian specimen of E. alcalophila are for the first time submitted to the GenBank.

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The identification of the diversity of microscopic fungi of lithobiont communities of the Argentine Islands in specimens collected during the 22nd Ukrainian Antarctic Expedition was the purpose of this work. Samples of rock, soil, mosses and lichens of rock micro-habitats of “Crustose lichen sub-formation and fruticose lichen and moss cushion sub-formation” were used in the work. These samples were used for extracting and cultivation of filamentous fungi on dense nutrient media. Determination of physiological and biochemical characteristics and identification of yeast-like fungi were performed using a microbiological analyser ‘Vitek-2’ (‘Bio Merieux’, France). Cultivation of microorganisms was carried out at temperatures from +2 to +37 °C. In results cultures of microscopic fungi of Zygomycota (Mucor circinelloides), Ascomycota (species of the genera cf. Tlielebolus, Talaromyces), representatives of the Anamorphic fungi group (Geomyces pannorum, species of the genera Alternaria, Acremonium, Aspergillus, Penicillium, and Cladosporium) were isolated from Antarctic samples. Microscopic fungi Penicillium spp. were dominated after the frequency in the studied samples (54.5%). Rhodotorula rubra and Candida sp. among isolated yeast fungi, and dark pigmented fungi represented by Aureobasidium pulhdans and Exophiala spp. were identified. The biological properties of a number of isolated fungi (the potential ability to synthesise important biologically active substances: melanins, carotenoids, lipids) are characterised. Mycobiota of rock communities of Argentine Islands is rich on filamentous and yeast fungi similarly to other regions of Antarctica. A number of fungi investigated are potentially able to synthesise biologically active substances. The dark pigmented species of the genera Cladosporium, Exophiala, Aureobasidium pulhdans, capable of melanin synthesis; ‘red’ yeast Rhodotorula rubra (carotenoid producers and resistant to toxic metals); Mucor circinelloides and Geomyces pannorum, lipid producers, are among these fungi. Yeast-like fungi assimilated a wide range of carbohydrates, which will allow them to be further used for cultivation in laboratory and process conditions. The collection of technologically promising strains of microorganisms, part of the Culture Collection of Fungi at Taras Shevchenko National University of Kyiv (Ukraine), is updated with isolated species (strains) of filamentous fungi and yeast – potential producers of biologically active substances, obtained within this study.

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New anamorph genus Pseudonadsoniella of dark brown yeast-like fungi similar to the genus Nadsoniella in having very slow growth in culture on all nutrient media but differing in showing better development of ‘colony-like formations’ on Saburo agar medium and potato sections as well as showing a phylogenetic affiliation to the family Meripilaceae (Polyporales, Agaricomycotina) after phylogenetic analysis based on ITS nrDNA sequences is described. The new species Pseudonadsoniella brunnea from Antarctic, Argentina, Galindez Island, is described and illustrated.

The position of some species groups appeared to be polyphyletic genera Rigidoporus, Physisporinus and Phaeococcomyces after ITS nrDNA sequences is discussed. Corrections to identification of some specimens of the genera Phlebia, Elmerina, Physisporinus are provided.

Nomenclature of Issatschenko’s species Nadsoniella nigra and its two infraspecific taxa as well as type and voucher confusion of these taxa in molecular study of the members of the genus Exophiala is discussed. It is shown that the anamorph fungus Exophiala sp. CBS 546.82 (VKM F-2137 or ‘voucher Ruban’s strain 365’), hitherto incorrectly recorded as Nadsoniella nigra var. hesuelica (nom. inval.), is a taxon still waiting for describing.

The conclusion that the original Issatschenko’s collection of Nadsoniella nigra (type strain CBS 535.94) and status of the strain Exophiala sp. CBS 546.82 are in urgent need of the modern revision/re-examination is done.

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