Abundance and diversity of diazotrophs in the surface sediments of Kongsfjorden, an Arctic fjord

Jabir, T.; Vipindas, Puthiya Veettil; Krishnan, K. P.; Hatha, A. A. Mohamed

doi:10.1007/s11274-020-02993-1

Cited by 11 publications

(1 citation statement)

References 72 publications

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“…The remaining six Arctic diazotrophs may represent new species within genera Arcobacter, Sunxiuqinia, Psychromonas, Oceanobacter, Immunodisolibacter, Novosphingobium (Table1 and Supplementary Data 1). Thus far, nifH of Arcobacter has been found in oceans around the globe including the Arctic Ocean 10,19,20 , and nifH of Novosphingobium was recently detected in deep waters in the subtropical ocean 21 . The diazotrophs within genera Sunxiuqinia, Psychromonas, Oceanobacter, and Immunodisolibacter were newly discovered in this study.…”

Section: Overall Characteristics Of Mags Containing Nifh That Were Re...mentioning

confidence: 99%

Distribution and survival strategies of diazotrophs in the Arctic Ocean revealed by global-scale metagenomic analysis

Shiozaki

Nishimura

Yoshizawa

et al. 2022

Preprint

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Nitrogen fixation is the major source of reactive nitrogen in the ocean and has been considered to occur specifically in low-latitude oligotrophic oceans. Recent studies have shown that nitrogen fixation also occurs in the polar regions and thus is a global process, although the physiological and ecological characteristics of polar diazotrophs are not yet known. Here, we successfully reconstructed genomes, including that of cyanobacterium UCYN-A (Candidatus "Atelocyanobacterium thalassa"), from metagenome data corresponding to 111 samples isolated from the Arctic Ocean. These diazotrophs were highly abundant in the Arctic Ocean (max., 1.28% of the total microbial community), suggesting that they have important roles in the Arctic ecosystem and biogeochemical cycles. Diazotrophs in the Arctic Ocean were either Arctic-specific or universal species. Arctic-specific diazotrophs, including Arctic UCYN-A, had unique gene sets (e.g., aromatics degradation) and/or a very small cell size (<0.2 μm), suggesting adaptations to Arctic-specific conditions. Universal diazotrophs were generally heterotrophs and commonly had the gene that encodes the cold-inducible RNA chaperone, which presumably makes their survival possible even in deep, cold waters and polar regions. Thus both types of diazotroph have physiological traits adaptable to their environments, which allow nitrogen fixation on a global scale.

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Section: Overall Characteristics Of Mags Containing Nifh That Were Re...mentioning

confidence: 99%

Distribution and survival strategies of diazotrophs in the Arctic Ocean revealed by global-scale metagenomic analysis

Shiozaki

Nishimura

Yoshizawa

et al. 2022

Preprint

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Stochastic Processes Dominate in the Water Mass–Based Segregation of Diazotrophs in a High Arctic Fjord (Svalbard)

et al. 2023

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Bacterial community structure and functional profiling of high Arctic fjord sediments

Vishnupriya

Jabir

Krishnan

et al. 2021

World J Microbiol Biotechnol

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Kongsfjorden, an Arctic fjord is signi cantly affected by the glacier melt and Atlanti cation, both the processes driven by accelerated warming in the Arctic. This has lead to changes in primary production, carbon pool and microbial communities, especially that in the sediment. In this study, we have examined the bacterial community structure of surface (0-2 cm) and subsurface (3-9 cm) sediments of Kongsfjorden using the high throughput sequencing analysis. Results revealed that bacterial community structure of Kongsfjorden sediments were dominated by phylum Proteobacteria followed by Bacteroidetes and Epsilonbacteraeota. While α-and γ-Proteobacterial class were dominant in surface sediments; δ-Proteobacteria were found to be predominant in subsurface sediments. The bacterial community structure in the surface and subsurface sediments showed signi cant variations (p ≤ 0.05). Total organic carbon could be one of the major parameters controlling the bacterial diversity in the surface and subsurface sediments. Functional prediction analysis indicated that the bacterial community could be involved in the degradation of complex organic compounds such as glycans, glycosaminoglycans, polycyclic aromatic hydrocarbons and also in the biosynthesis of secondary metabolites. IntroductionMarine sediment depicts most complex microbial habitats on earth. Benthic bacterial communities in the ocean play a signi cant role in remineralization of organic matter (Ravenschlag et al. 2000). Marine microorganisms hydrolyse high molecular weight organic matter to su ciently small constituents for their cellular intake and also make them easily available for higher trophic levels. Bacteria and archaea are the dominant microbial communities in marine sediments. These sediment communities are impacted by several physical and chemical parameters (Nguyen and Landfald, 2015;Jorgensen et al. 2012) and can be sensitive to environmental changes and are also affected by geographic distance and ocean currents (Hamdan et al. 2013;Xiong et al. 2014). Hence microbial community composition analysis is important to understand the benthic ecosystem processes and thereby to study about the effect of climate change.Kongsfjorden, located on the northwest coast of Spitsbergen in the Svalbard Archipelago is a tide water glacial fjord in the Arctic. Atlantic water in ow as well as several glaciers in uence the water column in the Kongsfjorden (Hop et al. 2002). The fjord is now identi ed as an ideal environment to study the impacts of climate change in the Arctic, indicated by the decrease in ice cover and a rise in melting. Physical gradients of salinity and temperature induced by the glacier melting, which generate turbidity and also sedimentation along the fjord system (Hop et al. 2002;Kotwicki et al. 2004) that ultimately affects the distribution of pelagic and benthic organisms (Kotwicki et al. 2004;Piquet et al. 2014). At the head of the fjord, tidal glaciers discharge fresh water and suspended loads, which generate steep environmental gradients (W sławs...

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Abundance and diversity of diazotrophs in the surface sediments of Kongsfjorden, an Arctic fjord

Cited by 11 publications

References 72 publications

Distribution and survival strategies of diazotrophs in the Arctic Ocean revealed by global-scale metagenomic analysis

Distribution and survival strategies of diazotrophs in the Arctic Ocean revealed by global-scale metagenomic analysis

Stochastic Processes Dominate in the Water Mass–Based Segregation of Diazotrophs in a High Arctic Fjord (Svalbard)

Bacterial community structure and functional profiling of high Arctic fjord sediments

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