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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Survival of Extremophilic Yeasts in the Stratospheric Environment during Balloon Flights and in Laboratory Simulations

Texto completo
Pulschen, Andre Arashiro [1] ; de Araujo, Gabriel Guarany [2] ; Souza Ramosde Carvalho, Ana Carolina [2] ; Cerini, Maria Fernanda [3, 4] ; Fonseca, Lucas de Mendonca [5] ; Galante, Douglas [3, 4] ; Rodrigues, Fabio [6]
Número total de Autores: 7
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Inst Chem, Sao Paulo - Brazil
[2] Univ Sao Paulo, Interun Grad Program Biotechnol, Sao Paulo - Brazil
[3] Brazilian Ctr Res Energy & Mat, Brazilian Synchrotron Light Lab, Campinas, SP - Brazil
[4] Univ Sao Paulo, Sao Carlos Inst Phys, Grad Program Biomol Phys, Sao Paulo - Brazil
[5] Airvantis P&D Ltda, Sao Carlos, SP - Brazil
[6] Univ Sao Paulo, Inst Chem, Dept Fundamental Chem, Sao Paulo - Brazil
Número total de Afiliações: 6
Tipo de documento: Artigo Científico
Fonte: Applied and Environmental Microbiology; v. 84, n. 23 DEC 2018.
Citações Web of Science: 3

The high-altitude atmosphere is a harsh environment with extremely low temperatures, low pressure, and high UV irradiation. For this reason, it has been proposed as an analogue for Mars, presenting deleterious factors similar to those on the surface of that planet. We evaluated the survival of extremophilic UV-resistant yeasts isolated from a high-elevation area in the Atacama Desert under stratospheric conditions. As biological controls, intrinsically resistant Bacillus subtilis spores were used. Experiments were performed in two independent stratospheric balloon flights and with an environmental simulation chamber. The three following different conditions were evaluated: (i) desiccation, (ii) desiccation plus exposure to stratospheric low pressure and temperature, and (3) desiccation plus exposure to the full stratospheric environment (UV, low pressure, and temperature). Two strains, Naganishia (Cryptococcus) friedmannii 16LV2 and Exophiala sp. strain 15LV1, survived full exposures to the stratosphere in larger numbers than did B. subtilis spores. Holtermanniella watticus (also known as Holtermanniella wattica) 16LV1, however, suffered a substantial loss in viability upon desiccation and did not survive the stratospheric UV exposure. The remarkable resilience of N. friedmannii and Exophiala sp. 15LV1 under the extreme Mars-like conditions of the stratosphere confirms its potential as a eukaryotic model for astrobiology. Additionally, our results with N. friedmannii strengthen the recent hypothesis that yeasts belonging to the Naganishia genus are fit for aerial dispersion, which might account for the observed abundance of this species in high-elevation soils. IMPORTANCE Studies of eukaryotic microorganisms under conditions of astrobiological relevance, as well as the aerial dispersion potential of extremophilic yeasts, are still lacking in the literature compared to works with bacteria. Using stratospheric balloon flights and a simulation chamber, we demonstrate that yeasts isolated from an extreme environment are capable of surviving all stressors found in the stratosphere, including intense UV irradiation, scoring an even higher survival than B. subtilis spores. Notably, the yeast N. friedmannii, which displayed one of the highest tolerances to the stratospheric environment in the experiments, was recently proposed to be adapted to airborne transportation, although such a hypothesis had not yet been tested. Our results strengthen such an assumption and can help explain the observed distribution and ecology of this particular yeast species. (AU)

Processo FAPESP: 09/06012-5 - Simulação multiparamétrica de ambientes extraterrestres
Beneficiário:Douglas Galante
Linha de fomento: Bolsas no Brasil - Pós-Doutorado
Processo FAPESP: 16/15054-7 - Simulações ambientais e caracterização espectroscópica in situ de potenciais bioassinaturas moleculares para aplicação em missões espaciais
Beneficiário:Maria Fernanda Cerini
Linha de fomento: Bolsas no Brasil - Mestrado