Bacterial community structure and functional profiling of high Arctic fjord sediments.

S. Vishnupriya,K. P. Krishnan,A. A. Mohamed Hatha,T. Jabir

doi:10.1007/s11274-021-03098-z

Abstract

Kongsfjorden, an Arctic fjord is significantly affected by the glacier melt and Atlantification, 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 (0-2cm) and subsurface (3-9cm) 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 significant 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.

Highlights

Marine sediment depicts most complex microbial habitats on earth
Compared to other stations Ca (Calcium) content was lower in surface sediment of station-1 and Fe (Iron) content was lower in subsurface sediment of station-4
When compared with previous reports, our results indicated that Proteobacteria were dominant in the Arctic marine sediment and within this phylum, γ- Proteobacteria were dominant in surface and δProteobacteria were seemed to be dominant in subsurface sediments of Kongsfjorden

Summary

Introduction

Marine sediment depicts most complex microbial habitats on earth. Benthic bacterial communities in the ocean play a significant role in remineralization of organic matter (Ravenschlag et al 2000). Marine microorganisms hydrolyse high molecular weight organic matter to sufficiently small constituents for their cellular intake and make them 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 affected by geographic distance and ocean currents (Hamdan et al 2013; Xiong et al 2014). Microbial community composition analysis is important to understand the benthic ecosystem processes and thereby to study about the effect of climate change

Objectives

Methods

Results

Discussion

Conclusion