Diurnal variation in bacterioplankton composition and DNA damage in the microbial community from an Andean oligotrophic lake

Fernández-Zenoff, María V.; Estévez, María Cristina; Farı́as, Marı́a Eugenia

doi:10.1016/s0325-7541(14)70095-1

Cited by 4 publications

(11 citation statements)

References 13 publications

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“…The detrimental effect of UV on community production from waters exposed to high solar radiation for long periods of time are significant, but lower than that of communities previously unexposed (Hernández et al, 2006; Santos et al, 2012). This is supported by observed differences in the presence of phototolerant strains between communities with different solar exposure histories (Fernández-Zenoff et al, 2006; Zenoff et al, 2014; Albarracín et al, 2016). …”

Section: Introductionmentioning

confidence: 63%

“…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%

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

et al. 2016

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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.

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Section: Introductionmentioning

confidence: 63%

Section: Introductionmentioning

confidence: 99%

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

et al. 2016

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“…Metagenomic approaches performed by Denaturing Gradient Gel Electrophoresis (DGGE), 16S rRNA gene clone libraries or 16s rDNA pyrotag sequencing indicated that prokaryotic communities from shallow water and sediment samples of HAAL are dominated by bacterial taxa of proteobacteria, bacteroidetes and firmicutes, whereas actinobacteria, cyanobacteria and spirochetes are less abundant (3,5,(7)(8)(9)11,12,14,(41)(42)(43)(45)(46)(47)69,70). Within Archaea, halophilic Euryarchaeota (Halobacteria), non-halophilic Euryarchaeota and mesophilic Crenarchaeota were described (11,24,43,69).…”

Section: Polyextremophiles: When One Extreme Is Not Enoughmentioning

confidence: 99%

“…Thus, HAAL provides natural laboratories for in situ exploring and monitoring of the interactions between the geophysical environment and the dynamics of microbiodiversity. Accordingly, HAAL-isolated strains display intrinsic high UV resistance (3)(4)(5)8,10,14,(16)(17)(18)(19) that render models for studying adaptive responses and mechanisms that underlie light sensing and UV resistance in environmental microbes. In fact, the availability of genomes of model polyextremophilic microbes (17,20) and several metagenomes of complex microbial communities in microbialites is providing a great opportunity to perform in-depth basic and applied research (4,6,19,(21)(22)(23)(24)(25)(26)(27)(28)(29).…”

Section: Introductionmentioning

confidence: 99%

Forged Under the Sun: Life and Art of Extremophiles from Andean Lakes

Albarracín

Gärtner

Farı́as

2015

Photochem & Photobiology

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High-altitude Andean lakes (HAAL) are a treasure chest for microbiological research in South America. Their indigenous microbial communities are exposed to extremely high UV irradiation and to multiple chemical extremes (Arsenic, high salt content, alkalinity). Microbes are found both, free-living or associated into microbial mats with different degrees of mineralization and lithification, including unique modern stromatolites located at 3570 m above sea level. Characterization of these polyextremophilic microbes began only recently, employing morphological and phylogenetic methods as well as high-throughput sequencing and proteomics approach. Aside from providing a general overview on microbial communities, special attention is given to various survival strategies; HAAL's microbes present a complex system of shared genetic and physiological mechanisms (UV-resistome) based on UV photoreceptors and stress sensors with their corresponding response regulators, UV avoidance and protection strategies, damage tolerance and UV damage repair. Molecular information will be provided for what is, so far the most studied HAAL molecule, a CPD-Class I photolyase from Acinetobacter Ver3 (Laguna Verde, 4400 m). This work further proposes some strategies that make an appeal for the preservation of HAAL, a highly fragile environment that offers promising and ample research possibilities.

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“…Indigenous microorganisms originally isolated from irradiated environment are in general well adapted to high UV exposure . This is also the case for HAAL's strains that display intrinsically high UV resistance and are now considered novel models for studying adaptive responses and mechanisms of light sensing and UV‐triggered mechanisms .…”

Section: Introductionmentioning

confidence: 99%

Photolyases and Cryptochromes in UV‐resistant Bacteria from High‐altitude Andean Lakes

Portero

Alonso-Reyes

Zannier

et al. 2019

Photochem & Photobiology

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“High‐altitude Andean Lakes” (HAAL) are pristine environments harboring poly‐extremophilic microbes that show combined adaptations to physical and chemical stress such as large daily ambient thermal amplitude, extreme solar radiation levels, intense dryness, alkalinity, high concentrations of arsenic (up to 200 ppm) and dissolved salts. In this work, we compared the UV resistance profiles, pigment content and photoreactivation abilities of three UV‐resistant bacteria isolated from distinct niches from HAALs, that is Acinetobacter sp. Ver3 (water, Lake Verde; 4400 m), Exiguobacterium sp. S17 (stromatolite, Lake Socompa, 3570 m) and Nesterenkonia sp. Act20 (soil, Lake Socompa, 3570 m). UV resistance ability of HAAL's strains indicate a clear adaptation to high radiation exposure encountered in their original habitat, which can be explained by genetic and physiological mechanisms named as the UV‐resistome. Thus, the UV‐resistome depends on the expression of a diverse set of genes devoted to evading or repairing the damage it provoked direct or indirectly. As pigment extraction and photoreactive assays indicate the presence of photoactive molecules, we characterized more in detail proteins with homology to photolyases/cryptochromes members (CPF). Phylogenetic analyses, sequence comparison and 3D modeling with bona fide CPF members were used to prove the presence of functional domains and key residues in the novel proteins.

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Diurnal variation in bacterioplankton composition and DNA damage in the microbial community from an Andean oligotrophic lake

Cited by 4 publications

References 13 publications

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

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

Forged Under the Sun: Life and Art of Extremophiles from Andean Lakes

Photolyases and Cryptochromes in UV‐resistant Bacteria from High‐altitude Andean Lakes

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