Microbial Mats of the McMurdo Dry Valleys, Antarctica: Oases of Biological Activity in a Very Cold Desert

Sohm, Jill A.; Niederberger, Thomas D.; Parker, Alexander E.; Tirindelli, Joëlle; Gunderson, Troy; Cary, S. Craig; Capone, Douglas G.; Carpenter, Edward

doi:10.3389/fmicb.2020.537960

Cited by 18 publications

(9 citation statements)

References 67 publications

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“…A similar general pattern was also observed elsewhere on the continent at high elevations in the Sør Rondane Mountains of Queen Maud Land (Tytgat et al, 2016). Likewise, higher soil moisture was correlated with higher rates of CO 2 and N 2 fixation in Nostoc-associated microbial mats in Miers Valley (Sohm et al, 2020). Also, the preponderance of Actinobacteria and the lack of Cyanobacteria in other cold-dry ecosystems outside of Antarctica is well known (e.g., An et al, 2013;Gupta et al, 2015).…”

Section: Discussion How Different Are Microbial Communities Among Habitats?supporting

confidence: 78%

Gullies and Moraines Are Islands of Biodiversity in an Arid, Mountain Landscape, Asgard Range, Antarctica

et al. 2021

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Cold, dry, and nutrient-poor, the McMurdo Dry Valleys of Antarctica are among the most extreme terrestrial environments on Earth. Numerous studies have described microbial communities of low elevation soils and streams below glaciers, while less is known about microbial communities in higher elevation soils above glaciers. We characterized microbial life in four landscape features (habitats) of a mountain in Taylor Valley. These habitats varied significantly in soil moisture and include moist soils of a (1) lateral glacial moraine, (2) gully that terminates at the moraine, and very dry soils on (3) a southeastern slope and (4) dry sites near the gully. Using rRNA gene PCR amplicon sequencing of Bacteria and Archaea (16S SSU) and eukaryotes (18S SSU), we found that all habitat types harbored significantly different bacterial and eukaryotic communities and that these differences were most apparent when comparing habitats that had macroscopically visible soil crusts (gully and moraine) to habitats with no visible crusts (near gully and slope). These differences were driven by a relative predominance of Actinobacteria and a Colpodella sp. in non-crust habitats, and by phototrophic bacteria and eukaryotes (e.g., a moss) and predators (e.g., tardigrades) in habitats with biological soil crusts (gully and moraine). The gully and moraine also had significantly higher 16S and 18S ESV richness than the other two habitat types. We further found that many of the phototrophic bacteria and eukaryotes of the gully and moraine share high sequence identity with phototrophs from moist and wet areas elsewhere in the Dry Valleys and other cold desert ecosystems. These include a Moss (Bryum sp.), several algae (e.g., a Chlorococcum sp.) and cyanobacteria (e.g., Nostoc and Phormidium spp.). Overall, the results reported here broaden the diversity of habitat types that have been studied in the Dry Valleys of Antarctica and suggest future avenues of research to more definitively understand the biogeography and factors controlling microbial diversity in this unique ecosystem.

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Section: Discussion How Different Are Microbial Communities Among Habitats?supporting

confidence: 78%

Gullies and Moraines Are Islands of Biodiversity in an Arid, Mountain Landscape, Asgard Range, Antarctica

et al. 2021

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“…Overall, the Archean Domes have a high diversity as seen in Chao (143-271), Shannon (2.5-3.1) and inverse At the genus level, we find Coleofasciculus as the most abundant Cyanobacteria between all samples, which is widely known as a key mat-forming genus in sandy environments (Noffke, 2010;Ramos et al, 2017;Prieto-Barajas et al, 2018;Cardoso et al, 2019). Other cyanobacterial genera such as Leptolyngbya, Halothece, and Phormidium are also abundant between samples, and have also been previously reported in microbial mats (Ramos et al, 2017;Sohm et al, 2020;Brenes-Guillén et al, 2021). Anaerobic, halophilic, sulfate-reducing members of the Deltaproteobacteria such as Desulfonatronovibrio, Desulfonatronospira and Desulfovermiculus also appear in abundance in the Archean Domes samples.…”

Section: Taxonomical Characterizationsupporting

confidence: 76%

Modern microbial mats from the Chihuahuan Desert provide insights into ecological stability throughout Earth’s history

Madrigal-Trejo

Sánchez-Pérez

Espinosa-Asuar

et al. 2021

Preprint

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Microbial mats are complex ecological assemblages that are found in the Precambrian fossil record and in extant extreme environments. Hence, these structures are regarded as highly stable ecosystems. In this work, we assess the ecological stability in a modern, fluctuating, hypersaline pond from the Cuatro Ciénegas Basin. From the 2016 to 2019 metagenomic sampling of this site, we found that this microbial site is sensitive to disturbances, which leads to high taxonomic replacement. Additionally, the mats have shown to be functionally stable throughout time, and could be differentiated between dry and rainy seasonal states. We speculate that this microbial system could represent modern analogs of ancient microbial mats where functions were preserved over time, whereas composition was subject to diversification in the face of local and planetary perturbations.

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“…One of Earth’s coldest dry deserts, the Antarctic Taylor Valley possesses a string of stratified lakes with unique geochemistry and microbial communities (1–4). The microbial genomic analysis of these lakes remains limited (5–7).…”

Section: Introductionmentioning

confidence: 99%

“…One of Earth’s coldest dry deserts, the McMurdo Dry Valleys in Antarctica possess a string of stratified lakes with unique geochemistry and microbial communities (Spigel & Priscu 1998, Roberts et al . 2004, Cavicchioli 2015, Sohm et al . 2020).…”

Section: Introductionmentioning

confidence: 99%

“…One of Earth's coldest dry deserts, the McMurdo Dry Valleys in Antarctica possess a string of stratified lakes with unique geochemistry and microbial communities (Spigel & Priscu 1998, Roberts et al 2004, Cavicchioli 2015, Sohm et al 2020. The microbial genomic analysis of these lakes remains limited (Dillon et al 2020, Koo et al 2018, Wei Li et al 2020.…”

Section: Introductionmentioning

confidence: 99%

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Antibiotic Resistance Genes and Taxa Analysis from Mat and Planktonic Microbiomes of Antarctic Perennial Ice-covered Lake Fryxell and Lake Bonney

Tallada

Hall

Barich

et al. 2021

Preprint

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The Antarctic Taylor Valley Lakes Fryxell and Bonney harbor oligotrophic microbial communities that are separated geographically from other aquatic systems. Their microbiomes include planktonic as well as lift-off mat communities that float to the underside of the perennial ice cover and eventually emerge at the surface. We investigated the antibiotic resistance genes (ARGs) from metagenomes of lift-off mats emerging from ice, from filtered water samples of Lake Fryxell, and from filtered water samples of Lake Bonney. ARG sequence markers were designed by ShortBRED-Identify using the Comprehensive Antibiotic Resistance Database (CARD). The overall proportion of ARG hits in the metagenomes was found to be similar to that found in temperate-zone rural water bodies with moderate human inputs (0.0002-0.0007%). The specific ARGs found showed distinct distributions for the two lakes, and for mat versus planktonic sources. An enrichment culture of Rhodoferax antarcticus from a Lake Fryxell mat sample showed a mat-forming phenotype not previously reported for this species. Its genome showed no ARGs associated with Betaproteobacteria, but had ARGs consistent with a Pseudomonas minor component. The Antarctic lake mats and water showed specific ARGs distinctive to the mat and water sources, but overall ARG levels were similar to those of temperate water bodies.

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Microbial Mats of the McMurdo Dry Valleys, Antarctica: Oases of Biological Activity in a Very Cold Desert

Cited by 18 publications

References 67 publications

Gullies and Moraines Are Islands of Biodiversity in an Arid, Mountain Landscape, Asgard Range, Antarctica

Gullies and Moraines Are Islands of Biodiversity in an Arid, Mountain Landscape, Asgard Range, Antarctica

Modern microbial mats from the Chihuahuan Desert provide insights into ecological stability throughout Earth’s history

Antibiotic Resistance Genes and Taxa Analysis from Mat and Planktonic Microbiomes of Antarctic Perennial Ice-covered Lake Fryxell and Lake Bonney

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