Description of Dioszegia patagonica sp. nov., a novel carotenogenic yeast isolated from cold environments.

During a survey of carotenogenic yeasts from cold and oligotrophic environments in Patagonia, several yeasts of the genus Dioszegia (Tremellales, Agaricomycotina) were detected, including three strains that could not be assigned to any known taxa. Analyses of internal transcribed spacer and D1/D2 regions of the large subunit rRNA gene showed these strains are conspecific with several other strains found in the Italian Alps and in Antarctica soil. Phylogenetic analyses showed that 19 of these strains represent a novel yeast species of the genus Dioszegia. The name Dioszegia patagonica sp. nov. is proposed to accommodate these strains and CRUB 1147T (UFMG 195T=CBMAI 1564T=DBVPG 10618T=CBS 14901T; MycoBank MB 819782) was designated as the type strain. This Dioszegia species accumulates biotechnologically valuable compounds such as carotenoid pigments and mycosporines.

Extracellular enzymatic activities of basidiomycetous yeasts isolated from glacial and subglacial waters of northwest Patagonia (Argentina).

As part of a project aimed at the selection of cold-adapted yeasts expressing biotechnologically interesting features, the extracellular enzymatic activity (EEA) of basidiomycetous yeasts isolated from glacial and subglacial waters of northwest Patagonia (Argentina) was investigated. Ninety-one basidiomycetous yeasts (belonging to the genera Cryptococcus, Leucosporidiella, Dioszegia, Mrakia, Rhodotorula, Rhodosporidium, Sporobolomyces, Sporidiobolus, Cystofilobasidium, and Udeniomyces) were screened for extracellular amylolytic, proteolytic, lipolytic, esterasic, pectinolytic, chitinolytic, and cellulolytic activities. Over 15% of the strains exhibited three or more different EEAs at 4 degrees C and more than 63% had at least two EEAs at the same temperature. No chitinolytic or cellulolytic activities were detected at 4 and 20 degrees C. Cell-free supernatants exhibited significantly higher (P < 0.01) protease and lipase activities at < or = 10 degrees C, or even at 4 degrees C. In light of these findings, cold environments of Patagonia (Argentina) may be considered a potential source of cold-adapted yeasts producing industrially relevant cold-active enzymes.