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 spoils (solonchaks) of Armenia (Arazdayan) and the Transaikal 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 CnPtococcus 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 ma-nitude. All of the isolates grew on acidic wort agar, suggesting that they did not include obligate alkaliphiles.