Taxonomic and phenotypic characterization of yeasts isolated from worldwide cold rock-associated habitats

• Psychrophilic lithic yeasts were isolated from worldwide rock samples.
• Yeasts were identified by 26S rDNA gene D1/D2 and ITS (1 and 2) sequencing.
• Cryptococcus and Rhodotorula were the most frequently isolated genera.
• A consistent part of yeasts (about 40 %) belong to species so far not described.
• Taxonomic and ecological significance is discussed.

Yeast strains isolated from rock samples collected from worldwide cold regions were identified by sequence analysis of the D1/D2 domains of the 26S rDNA gene and the ITS region followed by molecular phylogeny. Over 77 % of yeasts isolates were Basidiomycota. Cryptococcus (orders Filobasidiales and Tremellales) and Rhodotorula (order Cystobasidiales) were the most frequent genera. About 40 % of yeast isolates belonged to undescribed species.Almost all isolates were psychrotolerant. Urease and esterase were the most widely extracellular enzymatic activity at 4 °C and 20 °C. None of the strains exhibited extracellular protease, DNAse, cellulase, chitinase, and laccase activity.The taxonomic and ecological significance of yeasts associated to worldwide cold rocky habitats is discussed.