Alkalitolerant yeasts from natural biotopes

Using a solid nutrient medium containing alkaline buffer (pH 10) and an antibiotic, alkalitolerant yeasts were isolated from samples of soda-rich saline soils (solonchaks) of Armenia (Arazdayan) and the Transbaikal Region (the Kungur Steppe). The species diversity of the yeast populations of the tested soda-rich soils was relatively insignificant. They only contained alkalitolerant representatives of asporogenic capsulated yeasts belonging to the species Cryptococcus laurentii, C. albidus, Rhodotorula glutinis, R. mucilaginosa, and Sporobolomyces roseus. C. laurentii representatives clearly dominated the isolates obtained, their number exceeding that of the other species by 2-3 orders of magnitude. All of the isolates grew on acidic wort agar, suggesting that they did not include obligate alkaliphiles.     

Mrakia curviuscula sp. nov.: A New Psychrophilic Yeast from Forest Substrates

Seven strains with similar characteristics from the laboratory collection of yeasts isolated from forest substrates collected in the central part of European Russia corresponded to none of the known yeast species. Based on the study of their life cycle, physiological characteristics, and the nucleotide composition of their DNA and taking into account the data of PCR analysis with universal primers, the strains were ascribed to a new psychrophilic yeast species, Mrakia curviuscula sp. nov.     

Alkalitolerant Yeasts from Natural Biotopes

Using a solid nutrient medium containing alkaline buffer (pH 10) and an antibiotic, alkalitolerant yeasts were isolated from samples of soda-rich saline soils (solonchaks) of Armenia (Arazdayan) and the Transbaikal region (the Kungur Steppe). The species diversity of the yeast populations of the tested soda-rich soils was relatively insignificant. They only contained alkalitolerant representatives of asporogenic capsulated yeasts belonging to the species Cryptococcus laurentii, C. albidus, Rhodotorula glutinis, R. mucilaginosa,and Sporobolomyces roseus. C. laurentii representatives clearly dominated the isolates obtained, their number exceeding that of the other species by two to three orders of magnitude. All of the isolates grew on acidic wort agar, suggesting that they did not include obligate alkaliphiles.     

Mrakia curviuscula sp. Nov.--a new species of psychrophilic yeasts from forest substrates

Seven strains with similar characteristics from the laboratory collection of yeasts isolated from forest substrates collected in the central part of European Russia corresponded to none of the known yeast species. Based on the study of their life cycle, physiological characteristics, and the nucleotide composition of DNA and taking into account the data of PCR analysis with universal primers, the strains were ascribed to a new psychrophilic yeast species, Mrakia curviuscula sp. nov.     

A new species of psychrophilic basidiomycetes yeast Leucosporidium fasciculatum sp. Nov

A psychrophilic yeast with a basidiomycetous developmental cycle and properties corresponding to the genus Leucosporidium Fell et al. was isolated from the fruiting body of the edible spring mushroom Gyromitra esculenta Pers. picked near Moscow. However, the isolate differed from all Leucosporidium species described to date in a number of characteristics. The results of the study of the developmental cycle and of the cultural, morphological, physiological, and biochemical properties of the new isolate, strain KBP Y-3696, allow it to be assigned to a new species of the genus Leucosporidium.     

A New Species of Psychrophilic Basidiomycetous Yeasts Leucosporidium fasciculatum sp. nov.

A psychrophilic yeast with a basidiomycetous developmental cycle and properties corresponding to the genusLeucosporidium Fell et al. was isolated from the fruiting body of the edible spring mushroom Gyromitra esculenta Pers. picked near Moscow. However, the isolate differed from all Leucosporidium species described to date in a number of characteristics. The results of the study of the developmental cycle and of the cultural, morphological, physiological, and biochemical properties of the new isolate, strain KBP Y-3696, allow it to be assigned to a new species of the genus Leucosporidium.