Isolation of UVC-Tolerant Bacteria from the Hyperarid Atacama Desert, Chile

Paulino-Lima, Ivan G.; Azua‐Bustos, Armando; Vicuña, Rafael; González-Silva, Carlos; Salas, Loreto; Teixeira, Lia Cardoso Rocha Saraiva; Rosado, Alexandre Soares; Leitão, Álvaro C.; Lage, Claudia

doi:10.1007/s00248-012-0121-z

Cited by 46 publications

(43 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unlike the dramatic changes in DGGE community profiles that are evident after more stressful treatments (e.g., nanoparticle exposure, [65] and ultraviolet radiation [76]), our results initially suggested, similar to others [6], that FTCs did not appear to radically shift bacterial community structure in a predictable, consistent way.…”

Section: Experimental Section: the Effect Of Simulated Freeze-thawsupporting

confidence: 76%

The Effect of Freeze-Thaw Conditions on Arctic Soil Bacterial Communities

Kumar

Grogan

Chu

et al. 2013

Biology

View full text Add to dashboard Cite

Climate change is already altering the landscape at high latitudes. Permafrost is thawing, the growing season is starting earlier, and, as a result, certain regions in the Arctic may be subjected to an increased incidence of freeze-thaw events. The potential release of carbon and nutrients from soil microbial cells that have been lysed by freeze-thaw transitions could have significant impacts on the overall carbon balance of arctic ecosystems, and therefore on atmospheric CO2 concentrations. However, the impact of repeated freezing and thawing with the consequent growth and recrystallization of ice on microbial communities is still not well understood. Soil samples from three distinct sites, representing Canadian geographical low arctic, mid-arctic and high arctic soils were collected from Daring Lake, Alexandra Fjord and Cambridge Bay sampling sites, respectively. Laboratory-based experiments subjected the soils to multiple freeze-thaw cycles for 14 days based on field observations (0 °C to −10 °C for 12 h and −10 °C to 0 °C for 12 h) and the impact on the communities was assessed by phospholipid fatty acid (PLFA) methyl ester analysis and 16S ribosomal RNA gene sequencing. Both data sets indicated differences in composition and relative abundance between the three sites, as expected. However, there was also a strong variation within the two high latitude sites in the effects of the freeze-thaw treatment on individual PLFA and 16S-based phylotypes. These site-based heterogeneities suggest that the impact of climate change on soil microbial communities may not be predictable a priori; minor differential susceptibilities to freeze-thaw stress could lead to a “butterfly effect” as described by chaos theory, resulting in subsequent substantive differences in microbial assemblages. This perspectives article suggests that this is an unwelcome finding since it will make future predictions for the impact of on-going climate change on soil microbial communities in arctic regions all but impossible.

show abstract

Section: Experimental Section: the Effect Of Simulated Freeze-thawsupporting

confidence: 76%

The Effect of Freeze-Thaw Conditions on Arctic Soil Bacterial Communities

Kumar

Grogan

Chu

et al. 2013

Biology

View full text Add to dashboard Cite

show abstract

“…The UV-C radiation is more energetic and bactericidal that longer UV wavelengths as UV-B and UV-A. Although not present on Earth, it composes a significant proportion of UV spectra on the Martian surface, due to the rarified atmosphere of the planet (Cockell et al 2000), therefore, having significant importance to astrobiology studies (Paulino-Lima et al 2013;Pulschen et al 2015). We observed that B. thermoruber and A. kestanbolensis displayed the best survival, scoring a good survival after UV-C irradiation, with a D 10 of 200 J/m 2 .…”

Section: Discussionmentioning

confidence: 99%

Surviving in hot and cold: psychrophiles and thermophiles from Deception Island volcano, Antarctica

et al. 2018

View full text Add to dashboard Cite

Polar volcanoes harbor unique conditions of extreme temperature gradients capable of selecting different types of extremophiles. Deception Island is a marine stratovolcano located at Maritime Antarctica that is notable for its pronounced temperature gradients over very short distances, reaching values up to 100 °C in the fumaroles, and subzero temperatures next to the glaciers. Due to these characteristics, Deception can be considered an interesting analogue of extraterrestrial environments. Our main goal in this study was to isolate thermophilic and psychrophilic bacteria from sediments associated with fumaroles and glaciers from two geothermal sites in Deception Island, comprising temperatures between 0 and 98 °C, and to evaluate their survivability to desiccation and UV-C radiation. Our results revealed that culturable thermophiles and psychrophiles were recovered among the extreme temperature gradient in Deception volcano, which indicates that these extremophiles remain alive even when the conditions do not comprise their growth range. The viability of culturable psychrophiles in hyperthermophilic environments is still poorly understood and our work showed the importance of future studies about their survival strategies in high temperatures. Finally, the spore-forming thermophilic isolates which we found have displayed good survival to desiccation and UV-C irradiation, which suggests their potential to be further explored in astrobiological studies.

show abstract

“…High levels of UV radiation are known to affect cell structure, function, and integrity (Häder et al, 2015). As a result, phototolerant or resistant microbial strains dominate in systems exposed to high solar radiation (Fernández-Zenoff et al, 2006; Flores et al, 2009; Paulino-Lima et al, 2013; Zenoff et al, 2014). In marine systems, bacterial secondary production (BSP) under solar radiation has been shown to depend on the solar exposure history (photobiological history) of the bacterioplankton community (Jeffrey et al, 1996a,b; Hernández et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

Microbial Activity Response to Solar Radiation across Contrasting Environmental Conditions in Salar de Huasco, Northern Chilean Altiplano

et al. 2016

View full text Add to dashboard Cite

In high altitude environments, extreme levels of solar radiation and important differences of ionic concentrations over narrow spatial scales may modulate microbial activity. In Salar de Huasco, a high-altitude wetland in the Andean mountains, the high diversity of microbial communities has been characterized and associated with strong environmental variability. Communities that differed in light history and environmental conditions, such as nutrient concentrations and salinity from different spatial locations, were assessed for bacterial secondary production (BSP, 3H-leucine incorporation) response from short-term exposures to solar radiation. We sampled during austral spring seven stations categorized as: (a) source stations, with recently emerged groundwater (no-previous solar exposure); (b) stream running water stations; (c) stations connected to source waters but far downstream from source points; and (d) isolated ponds disconnected from ground sources or streams with a longer isolation and solar exposure history. Very high values of 0.25 μE m-2 s-1, 72 W m-2 and 12 W m-2 were measured for PAR, UVA, and UVB incident solar radiation, respectively. The environmental factors measured formed two groups of stations reflected by principal component analyses (near to groundwater sources and isolated systems) where isolated ponds had the highest BSP and microbial abundance (35 microalgae taxa, picoeukaryotes, nanoflagellates, and bacteria) plus higher salinities and PO43- concentrations. BSP short-term response (4 h) to solar radiation was measured by 3H-leucine incorporation under four different solar conditions: full sun, no UVB, PAR, and dark. Microbial communities established in waters with the longest surface exposure (e.g., isolated ponds) had the lowest BSP response to solar radiation treatments, and thus were likely best adapted to solar radiation exposure contrary to ground source waters. These results support our light history (solar exposure) hypothesis where the more isolated the community is from ground water sources, the better adapted it is to solar radiation. We suggest that factors other than solar radiation (e.g., salinity, PO43-, NO3-) are also important in determining microbial productivity in heterogeneous environments such as the Salar de Huasco.

show abstract

Isolation of UVC-Tolerant Bacteria from the Hyperarid Atacama Desert, Chile

Cited by 46 publications

References 25 publications

The Effect of Freeze-Thaw Conditions on Arctic Soil Bacterial Communities

The Effect of Freeze-Thaw Conditions on Arctic Soil Bacterial Communities

Surviving in hot and cold: psychrophiles and thermophiles from Deception Island volcano, Antarctica

Microbial Activity Response to Solar Radiation across Contrasting Environmental Conditions in Salar de Huasco, Northern Chilean Altiplano

Contact Info

Product

Resources

About