title: Identification and characterization of yeasts isolated from sedimentary rocks of Union Glacier at the Antarctica.
abstract: The study of the yeasts that inhabit cold environments, such as Antarctica, is an active field of investigation oriented toward understanding their ecological roles in these ecosystems. In a great part, the interest in cold-adapted yeasts is due to several industrial and biotechnological applications that have been described for them. The aim of this work was to isolate and identify yeasts from sedimentary rock samples collected at the Union Glacier, Antarctica. Furthermore, the yeasts were physiologically characterized, including the production of metabolites of biotechnological interest. The yeasts isolated that were identified at the molecular level belonged to genera Collophora (1 isolate), Cryptococcus (2 isolates), Sporidiobolus (4 isolates), Sporobolomyces (1 isolate) and Torrubiella (2 isolates). The majority of yeasts were basidiomycetous and psychrotolerant. By cross-test assays for anti-yeast activity, it was determined that Collophora sp., Sporidiobolus salmonicolor, and Sporobolomyces roseus secreted a protein factor that kills Sporidiobolus metaroseus. The colored yeasts Sp. salmonicolor, Sp. metaroseus and Collophora sp. produced several carotenoid pigments that were identified as 2,3 dihydroxy-γ-carotene, -carotene, 4-ketotorulene, torulene β-cryptoxanthin and spirilloxanthin. Concerning analysis of mycosporines, these metabolites were only found in the yeasts Torrubiella sp. and Cryptococcus sp. T11-10-1. Furthermore, the yeasts were evaluated for the production of extracellular hydrolytic activities. Of the twelve activities analyzed, alkaline phosphatase, invertase, gelatinase, cellulase, amylase, and protease enzyme activities were detected. The yeasts Cryptococcus sp. T11-10-1 and Sporidiobolus metaroseus showed the highest number of different enzyme activities.
authors.affiliation: Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
authors.forename: Salvador
authors.initials: S
authors.lastname: Barahona
authors.affiliation: Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
authors.forename: Yassef
authors.initials: Y
authors.lastname: Yuivar
authors.affiliation: Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Socias
authors.affiliation: Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Alcaíno
authors.affiliation: Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile.
authors.forename: Víctor
authors.initials: V
authors.lastname: Cifuentes
authors.affiliation: Laboratorio de Genética, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Universidad de Chile, Las Palmeras 3425, Casilla 653, Santiago, Chile. mbaeza@u.uchile.cl.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Baeza
mesh_terms: D000864:Antarctic Regions; D002338:Carotenoids / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D019015:Geologic Sediments / Q000382:microbiology*; D046448:Ice Cover / Q000382:microbiology*; D007218:Industrial Microbiology; D010447:Peptide Hydrolases / Q000235:genetics / Q000378:metabolism; D015003:Yeasts / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D005656:Fungal Proteins; D002338:Carotenoids; D010447:Peptide Hydrolases
keywords: Carotenoids; Cold-active enzymes; Mycosporines; Psychrotolerant yeasts; Union Glacier