UV‐resistant yeasts isolated from a high‐altitude volcanic area on the Atacama Desert as eukaryotic models for astrobiology

MicrobiologyOpen

André A. Pulschen⁵  Fabio Rodrigues⁵  Rubens T. D. Duarte¹  Gabriel G. Araujo²  Iara F. Santiago⁶  Ivan G. Paulino-Lima³  Carlos A. Rosa⁶  Massuo J. Kato⁵  Vivian H. Pellizari⁴ 

[1] Microbiology, Immunology and Parasitology Department, Universidade Federal de Santa Catarina, Florianópolis, Brazil;Interunities Graduate Program in Biotechnology, Universidade de São Paulo, São Paulo, Brazil;NASA Postdoctoral Program Fellow at NASA Ames Research Center, Moffett Field, California;Oceanographic Institute, Universidade de São Paulo, São Paulo, Brazil;Chemistry Institute, Universidade de São Paulo, São Paulo, Brazil;Department of Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil

关键词: Astrobiology;    Atacama Desert;    eukaryote;    extremophiles;    UV radiation;    yeast;   

DOI  :  10.1002/mbo3.262

来源: Wiley

【 摘 要 】

Abstract

The Sairecabur volcano (5971 m), in the Atacama Desert, is a high-altitude extreme environment with high daily temperature variations, acidic soils, intense UV radiation, and low availability of water. Four different species of yeasts were isolated from this region using oligotrophic media, identified and characterized for their tolerance to extreme conditions. rRNA sequencing revealed high identity (>98%) to Cryptococcus friedmannii, Exophiala sp., Holtermanniella watticus, and Rhodosporidium toruloides. To our knowledge, this is the first report of these yeasts in the Atacama Desert. All isolates showed high resistance to UV-C, UV-B and environmental-UV radiation, capacity to grow at moderate saline media (0.75–2.25 mol/L NaCl) and at moderate to cold temperatures, being C. friedmannii and H. watticus able to grow in temperatures down to −6.5°C. The presence of pigments, analyzed by Raman spectroscopy, correlated with UV resistance in some cases, but there is evidence that, on the natural environment, other molecular mechanisms may be as important as pigmentation, which has implications for the search of spectroscopic biosignatures on planetary surfaces. Due to the extreme tolerances of the isolated yeasts, these organisms represent interesting eukaryotic models for astrobiological purposes.

【 授权许可】

CC BY   
© 2015 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

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