Taxonomic and functional stability overrules seasonality in polar benthic microbiomes.

Autor:	Miksch S; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany., Orellana LH; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany., Oggerin de Orube M; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany., Vidal-Melgosa S; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.; MARUM MPG Bridge Group Marine Glycobiology, Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany., Solanki V; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany., Hehemann JH; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.; MARUM MPG Bridge Group Marine Glycobiology, Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany., Amann R; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany., Knittel K; Department of Molecular Ecology, Max Planck Institute for Marine Microbiology, 28359 Bremen, Germany.
Jazyk:	angličtina
Zdroj:	The ISME journal [ISME J] 2024 Jan 08; Vol. 18 (1).
DOI:	10.1093/ismejo/wrad005
Abstrakt:	Coastal shelf sediments are hot spots of organic matter mineralization. They receive up to 50% of primary production, which, in higher latitudes, is strongly seasonal. Polar and temperate benthic bacterial communities, however, show a stable composition based on comparative 16S rRNA gene sequencing despite different microbial activity levels. Here, we aimed to resolve this contradiction by identifying seasonal changes at the functional level, in particular with respect to algal polysaccharide degradation genes, by combining metagenomics, metatranscriptomics, and glycan analysis in sandy surface sediments from Isfjorden, Svalbard. Gene expressions of diverse carbohydrate-active enzymes changed between winter and spring. For example, β-1,3-glucosidases (e.g. GH30, GH17, GH16) degrading laminarin, an energy storage molecule of algae, were elevated in spring, while enzymes related to α-glucan degradation were expressed in both seasons with maxima in winter (e.g. GH63, GH13_18, and GH15). Also, the expression of GH23 involved in peptidoglycan degradation was prevalent, which is in line with recycling of bacterial biomass. Sugar extractions from bulk sediments were low in concentrations during winter but higher in spring samples, with glucose constituting the largest fraction of measured monosaccharides (84% ± 14%). In porewater, glycan concentrations were ~18-fold higher than in overlying seawater (1107 ± 484 vs. 62 ± 101 μg C l-1) and were depleted in glucose. Our data indicate that microbial communities in sandy sediments digest and transform labile parts of photosynthesis-derived particulate organic matter and likely release more stable, glucose-depleted residual glycans of unknown structures, quantities, and residence times into the ocean, thus modulating the glycan composition of marine coastal waters. (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Microbial Ecology.)
Databáze:	MEDLINE
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