Bacterial community changes with granule size in cryoconite and their susceptibility to exogenous nutrients on NW Greenland glaciers

Uetake, Jun; Nagatsuka, Naoko; Onuma, Yukihiko; Takeuchi, Nozomu; Motoyama, Hideaki; Aoki, Teruo

doi:10.1093/femsec/fiz075

Cited by 20 publications

(24 citation statements)

References 47 publications

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“…The most abundant cyanobacterial RSVs were also found in soils of the Wright Valley (Tychonema: GenBank: KM052830.1; 100% similarity), Antarctic snow (Lopatina et al, 2013;GenBank: JX855325., 99.63% similarity). Filamentous Cyanobacteria play a key role in cryoconite granule formation (Jungblut and Vincent, 2017) and the granule size shapes the microbial community composition (Uetake et al, 2019). Here, typical cryoconite granule engineers (Phormidium, Chamaesiphon) were present but the granules were neither observed in other Antarctic regions.…”

Section: Extremely Low Nutrient Levels Do Not Support High Rates Of Mmentioning

confidence: 85%

Cryoconite Hole Location in East-Antarctic Untersee Oasis Shapes Physical and Biological Diversity

et al. 2020

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Antarctic cryoconite holes (CHs) are mostly perennially ice-lidded and sediment-filled depressions that constitute important features on glaciers and ice sheets. Once being hydrologically connected, these microbially dominated mini-ecosystems provide nutrients and biota for downstream environments. For example, the East Antarctic Anuchin Glacier gradually melts into the adjacent perennially ice-covered Lake Untersee, and CH biota from this glacier contribute up to one third of the community composition in benthic microbial mats within the lake. However, biogeochemical features of these CHs and associated spatial patterns across the glacier are still unknown. Here we hypothesized about the CH minerogenic composition between the different sources such as the medial moraine and other zones. Further, we intended to investigate if the depth of the CH mirrors the CH community composition, organic matter (OM) content and would support productivity. In this study we show that both microbial communities and biogeochemical parameters in CHs were significantly different between the zones medial moraine and the glacier terminus. Variations in microbial community composition are the result of factors such as depth, diameter, organic matter, total carbon, particle size, and mineral diversity. More than 90% of all ribosomal sequence variants (RSV) reads were classified as Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacteria, and Acidobacteria. Archaea were detected in 85% of all samples and exclusively belonged to the classes Halobacteria, Methanomicrobia, and Thermoplasmata. The most abundant genus was Halorubrum (Halobacteria) and was identified in nine RSVs. The core microbiome for bacteria comprised 30 RSVs that were affiliated with Cyanobacteria, Bacteroidetes, Actinobacteria, and Proteobacteria. The archaeal fraction of the core microbiome consisted of three RSVs belonging to unknown genera of Methanomicrobiales and Thermoplasmatales and the genus Rice_Cluster_I (Methanocellales). Further, mean bacterial carbon production in cryoconite was exceptionally low and similar rates have not been reported elsewhere. However, bacterial carbon production insignificantly trended toward higher rates in shallow CHs and did not seem to be supported by accumulation of OM and nutrients, respectively, in deeper holes. OM fractions were significantly different between shallower CHs along

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Section: Extremely Low Nutrient Levels Do Not Support High Rates Of Mmentioning

confidence: 85%

Cryoconite Hole Location in East-Antarctic Untersee Oasis Shapes Physical and Biological Diversity

et al. 2020

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“…The other cyanobacterial organisms present in our dataset were present in a lower percentage (1%) compared to Nostoc (4%); between them, there are, for example, Phormidesmis and Chamaesiphon . These organisms are typical of the cold environments and do not perform nitrogen fixation ( Jungblut and Vincent, 2017 ; Segawa et al, 2017 ; Uetake et al, 2019 ). In the soil, diazotrophic organisms belonging to Proteobacteria and Actinobacteria were more abundant ( Figure 7 ).…”

Section: Discussionmentioning

confidence: 99%

A Taxon-Wise Insight Into Rock Weathering and Nitrogen Fixation Functional Profiles of Proglacial Systems

2021

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The Arctic environment is particularly affected by global warming, and a clear trend of the ice retreat is observed worldwide. In proglacial systems, the newly exposed terrain represents different environmental and nutrient conditions compared to later soil stages. Therefore, proglacial systems show several environmental gradients along the soil succession where microorganisms are active protagonists of the soil and carbon pool formation through nitrogen fixation and rock weathering. We studied the microbial succession of three Arctic proglacial systems located in Svalbard (Midtre Lovénbreen), Sweden (Storglaciären), and Greenland (foreland close to Kangerlussuaq). We analyzed 65 whole shotgun metagenomic soil samples for a total of more than 400 Gb of sequencing data. Microbial succession showed common trends typical of proglacial systems with increasing diversity observed along the forefield chronosequence. Microbial trends were explained by the distance from the ice edge in the Midtre Lovénbreen and Storglaciären forefields and by total nitrogen (TN) and total organic carbon (TOC) in the Greenland proglacial system. Furthermore, we focused specifically on genes associated with nitrogen fixation and biotic rock weathering processes, such as nitrogenase genes, obcA genes, and genes involved in cyanide and siderophore synthesis and transport. Whereas we confirmed the presence of these genes in known nitrogen-fixing and/or rock weathering organisms (e.g., Nostoc, Burkholderia), in this study, we also detected organisms that, even if often found in soil and proglacial systems, have never been related to nitrogen-fixing or rock weathering processes before (e.g., Fimbriiglobus, Streptomyces). The different genera showed different gene trends within and among the studied systems, indicating a community constituted by a plurality of organisms involved in nitrogen fixation and biotic rock weathering, and where the latter were driven by different organisms at different soil succession stages.

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“…Common to all sampling sites were taxa previously found and isolated from other polar and cold environments, such as the genera Phormidesmis (Chrismas and others, 2016), Salinibacterium (Shin and others, 2012), Solitalea (Uetake and others, 2019), Granulicella (Oshkin and others, 2019) and Hymenobacter (Klassen and Foght, 2011). Most of these taxa have been described as being exopolysaccharide (EPS), ice-binding protein and antifreeze protein producers (Cid and others, 2016; Kielak and others, 2016; Chrismas and others, 2018).…”

Section: Discussionmentioning

confidence: 92%

“…Therefore, as they formed at different times they would reflect the environment at that time and source region on the glacier. Importantly, microbial communities are strongly correlated with variations in nutrient and particle concentration, which can vary by some magnitude, spatially and temporally (Dieser and others, 2010; Lutz and others, 2016; Uetake and others, 2019).…”

Section: Discussionmentioning

confidence: 99%

“…Glacial biomes are microbially dominated and are usually divided into three different environments: the glacial surface (supraglacial), within its interior (englacial) and at the base where the glacier is in contact with the bedrock (subglacial) (Anesio and others, 2017; García-López and others, 2019a). Supraglacial studies have mainly been focused on cryoconite holes (Fountain and others, 2004; Tranter and others, 2004; Bagshaw and others, 2007; Edwards and others, 2011; Musilova and others, 2015; Cook and others, 2016; Uetake and others, 2019) and ice algae-associated communities (Uetake and others, 2010; Yallop and others, 2012; Lutz and others, 2017), both of which are dominated by phototrophs. Here, microbial communities are highly influenced by the surrounding environment from which wind and precipitation transport dust, larger particles and, consequently, nutrients and microorganisms to the glacier surface (Grzesiak and others, 2015).…”

Section: Introductionmentioning

confidence: 99%

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Glacier clear ice bands indicate englacial channel microbial distribution

et al. 2021

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Distant glacial areas are interconnected by a complex system of fractures and water channels which run in the glacier interior and characterize the englacial realm. Water can slowly freeze in these channels where the slow freezing excludes air bubbles giving the ice a clear aspect. This ice is uplifted to the surface ablation zone by glacial movements and can therefore be observed in the form of clear surface ice bands. We employed an indirect method to sample englacial water by coring these ice bands. We were able, for the first time, to compare microbial communities sampled from clear (i.e. frozen englacial water bands) and cloudy ice (i.e. meteoric ice) through 16S rRNA gene sequencing. Although microbial communities were primarily shaped and structured by their spatial distribution on the glacier, ice type was a clear secondary factor. One area of the glacier, in particular, presented significant microbial community clear/cloudy ice differences. Although the clear ice and supraglacial communities showed typical cold-adapted glacial communities, the cloudy ice had a less defined glacial community and ubiquitous environmental organisms. These results highlight the role of englacial channels in the microbial dispersion within the glacier and, possibly, in the shaping of glacial microbial communities.

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Bacterial community changes with granule size in cryoconite and their susceptibility to exogenous nutrients on NW Greenland glaciers

Cited by 20 publications

References 47 publications

Cryoconite Hole Location in East-Antarctic Untersee Oasis Shapes Physical and Biological Diversity

Cryoconite Hole Location in East-Antarctic Untersee Oasis Shapes Physical and Biological Diversity

A Taxon-Wise Insight Into Rock Weathering and Nitrogen Fixation Functional Profiles of Proglacial Systems

Glacier clear ice bands indicate englacial channel microbial distribution

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