Snow and ice ecosystems: not so extreme

Maccario, Lorrie; Sanguino, Laura; Vogel, Timothy M.; Larose, Catherine

doi:10.1016/j.resmic.2015.09.002

Cited by 62 publications

(61 citation statements)

References 208 publications

(170 reference statements)

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“…We interpret these data to demonstrate that ice algal assemblages are the main producers of the dissolved organic nutrient stocks within the melting surface ice of the GrIS, consistent with previous studies in glacial, freshwater and marine aquatic environments (Musilova et al, 2017;Johannes and Webb, 1970;Lampert, 1978). Ice algae that bloom in these environments rapidly uptake inorganic nutrients, which are derived from a number of possible sources, including the atmosphere, wet and dry deposition, and snow and ice-melt (Kuhn, 2001;Maccario et al, 2015). This results in an increase in the mass of nutrients held in the microbial biomass, and an increase in dissolved organic nutrients as a by-product of the vital intracellular processes and decomposition of the ice algae.…”

Section: Association Of Dissolved Organic Nutrients and Algal Abundancesupporting

confidence: 87%

Nutrient cycling in supraglacial environments of the Dark Zone of the Greenland Ice Sheet

Holland

Williamson

Sgouridis

et al. 2019

Preprint

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<p><strong>Abstract.</strong> Glaciers and ice sheets host abundant and dynamic communities of microorganisms on the ice surface (supraglacial environments). Recently, it has been shown that Streptophyte ice algae blooming on the surface ice of the south-west coast of the Greenland Ice Sheet are a significant contributor to the 15-year marked decrease in albedo. Currently little is known about the constraints, such as the nutrient cycling, on this large-scale algal bloom. In this study, we present a preliminary data set that investigates the conversion of dissolved inorganic nutrients to the dissolved organic phase occurring in these darkening surface ice environments. Our results show a clear dominance of the organic phase, with 93&#8201;% of the total dissolved nitrogen and 67&#8201;% of the total dissolved phosphorus in the organic phase. Correlations between algal abundance and dissolved organic carbon and nitrogen, indicate ice algae are driving the dissolved nutrient phase shift occurring in these supraglacial environments. Dissolved organic nutrient ratios in these supraglacial environments are notably higher than the Redfield Ratio (DON&#8201;:&#8201;DOP&#8201;=&#8201;49, 78, 116) and DOC&#8201;:&#8201;DOP&#8201;=&#8201;797, 1166, 2013), suggesting these environments may be phosphorus limited.</p>

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Section: Association Of Dissolved Organic Nutrients and Algal Abundancesupporting

confidence: 87%

Nutrient cycling in supraglacial environments of the Dark Zone of the Greenland Ice Sheet

Holland

Williamson

Sgouridis

et al. 2019

Preprint

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“…For instance, microorganisms living in hyperarid regions or hypersaline aquatic environments are frequently exposed to desiccation or hypertonicity 31 . Also, microbes in snow and ice habitats experience low water availability and hypersaline or hyper-acidic environments 32 Bacteria can adapt to these fluctuations by modulating fatty acid synthesis, accumulating or synthesizing osmoprotectants, protecting their DNA, and secreting extracellular polymeric substance 31, 33 .…”

Section: Discussionmentioning

confidence: 99%

Stress-induced formation of cell wall-deficient cells in filamentous actinomycetes

Ramijan

Ultee

Willemse

et al. 2016

Preprint

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The cell wall is a shape-defining structure that envelopes almost all bacteria. One of its main functions is to serve as a protection barrier to environmental stresses. Bacteria can be forced in a cell wall-deficient state under highly specialized conditions, which are invariably aimed at interrupting cell wall synthesis. Therefore, the relevance of such cells has remained obscure. Here we show that many filamentous actinomycetes have a natural ability to generate a new, cell wall-deficient cell type in response to hyperosmotic stress, which we call S-cells. This wall-deficient state is transient, as S-cells are able to switch to the canonical mycelial mode-of-growth. Remarkably, prolonged exposure of S-cells to hyperosmotic stress yielded variants that are able to proliferate indefinitely without their cell wall. This is the first report that demonstrates the formation of wall-deficient cells as a natural adaptation strategy and their potential transition into stable wall-less forms solely caused by prolonged exposure to osmotic stress. Given that actinomycetes are potent antibiotic producers, our work also provides important insights into how biosynthetic gene clusters and resistance determinants may disseminate into the environment.

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“…Even though cold environments have long been regarded as extreme due to low temperatures, low water and nutrient availability and high levels of UV radiation, they are actively inhabited by a variety of microorganisms (Maccario et al 2015). Ecosystems such as tundra, permafrost, and glaciers are regarded as biomes, harboring species from the Bacteria, Archaea, and Eukarya domains (Wagner 2008;Kirby et al 2012) and constitute major pools of genomic diversity (Edwards 2015).…”

Section: Introductionmentioning

confidence: 99%

Potentially pathogenic bacteria isolated from diverse habitats in Spitsbergen, Svalbard

2020

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The Arctic ecosystem, a reservoir of genetic microbial diversity, represents a virtually unlimited source of microorganisms that could interact with human beings. Despite continuous exploration of Arctic habitats and description of their microbial communities, bacterial phenotypes commonly associated with pathogenicity, such as hemolytic activity, have rarely been reported. In this study, samples of snow, fresh and marine water, soil, and sediment from several habitats in the Arctic archipelago of Svalbard were collected during Summer, 2017. Bacterial isolates were obtained after incubation on oligotrophic media at different temperatures and their hemolytic potential was assessed on sheep blood agar plates. Partial (α) or true (β) hemolysis was observed in 32 out of 78 bacterial species. Genes expressing cytolytic compounds, such as hemolysins, likely increase the general fitness of the producing microorganisms and confer a competitive advantage over the availability of nutrients in natural habitats. In environmental species, the nutrient-acquisition function of these compounds presumably precedes their function as toxins for mammalian erythrocytes. However, in the light of global warming, the presence of hemolytic bacteria in Arctic environments highlights the possible risks associated with these microorganisms in the event of habitat melting/destruction, ecosystem transition, and re-colonization.

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Snow and ice ecosystems: not so extreme

Cited by 62 publications

References 208 publications

Nutrient cycling in supraglacial environments of the Dark Zone of the Greenland Ice Sheet

Nutrient cycling in supraglacial environments of the Dark Zone of the Greenland Ice Sheet

Stress-induced formation of cell wall-deficient cells in filamentous actinomycetes

Potentially pathogenic bacteria isolated from diverse habitats in Spitsbergen, Svalbard

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