Characterization of basidiomycetous yeasts in hypersaline soils of the Urmia Lake National Park,Iran

Urmia Lake, located in northwest Iran, is an oligotrophic and extremely hypersaline habitat that supports diverse forms of life. Owing to its unique biodiversity and special environmental conditions, Urmia Lake National Park has been designated as one of the biosphere reserves by UNESCO. This study was aimed to characterize basidiomycetous yeasts in hypersaline soils surrounding the Urmia Lake National Park using a polyphasic combination of molecular and physiological data. Soil samples were collected from eight sites in Lake Basin and six islands insides the lake. Yeast strains were identified by sequencing the D1/D2 domains of the 26S rRNA gene. When D1/D2 domain sequencing did not resolve the identity of the species, strain identification was obtained by ITS 1 & 2 sequencing. Twenty-one species belonging to the genera Cystobasidium, Holtermanniella, Naganishia, Rhodotorula, Saitozyma, Solicoccozyma, Tausonia, Vanrija, and Vishniacozyma were identified. Solicoccozyma aeria represented the dominant species. The ability of isolates to grow at 10 and 15 % of NaCl was checked; about two-thirds of the strains grew at 10 %, while about 13 % of the isolates grew in medium with 15 % NaCl. this study is the first study on the culturable yeast diversity in hypersaline soils surrounding an Asian lake.