Biodiversity of cold-adapted yeasts from runoff glacial rivers in Patagonia, Argentina

DE GARCÍA, V; BRIZZIO S,; LIBKIND FRATI, D; BUZZINI, P; VAN BROOCK, M

FEMS MICROBIOLOGY ECOLOGY

Blackwell Publishing Ltd.

Lugar: Oxford; Año: 2007 vol. 59 p. 331 - 341

0168-6496

The occurrence of culturable yeasts in glacial meltwater from the Frıas, Castaño Overo and Rıo Manso glaciers, located on Mount Tronador in the Nahuel Huapi National Park (Northwestern Patagonia, Argentina) is presented. Subsurface water samples were filtered for colony counting and yeast isolation. The total yeast count ranged between 6 and 360 CFU L–1. Physiologic and molecular methods were employed to identify 86 yeast isolates. In agreement with yeast diversity data from studies for Antarctic and Alpine glaciers, the genera Cryptococcus, Leucosporidiella, Dioszegia, Rhodotorula, Rhodosporidium, Mrakia, Sporobolomyces, Udeniomyces and Candida were found. Cryptococcus and Leucosporidiella accounted for 50% and 20% of the total number of strains, respectively. Among 21 identified yeast species, Cryptococcus sp. 1 and Leucosporidiella fragaria were the most frequent. The typically psychrophilic Mrakia yeast strain and three new yeast species, yet to be described, were also isolated. All yeast strains were able to grow at 5, 10, and 15 °C. Among yeast strains expressing extracellular enzymatic activity, higher proteolytic and lipolytic activities were obtained at 4 °C than at 20 °C.