Ontology highlight
ABSTRACT:
PROVIDER: PRJNA861000 | ENA |
REPOSITORIES: ENA
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Project description:Salt marshes provide many key ecosystem services that have tremendous ecological and economic value. One critical service is the removal of fixed nitrogen from coastal waters, which limits the negative effects of eutrophication resulting from increased nutrient supply. Nutrient enrichment of salt marsh sediments results in higher rates of nitrogen cycling and, commonly, a concurrent increase in the flux of nitrous oxide, an important greenhouse gas. Little is known, however, regarding controls on the microbial communities that contribute to nitrous oxide fluxes in marsh sediments. To address this disconnect, we generated microbial community profiles as well as directly assayed nitrogen cycling genes that encode the enzymes responsible for overall nitrous oxide flux from salt marsh sediments. We hypothesized that communities of microbes responsible for nitrogen transformations will be structured by nitrogen availability. Taxa that respond positively to high nitrogen inputs may be responsible for the elevated rates of nitrogen cycling processes measured in fertilized sediments. Our data show that, with the exception of ammonia-oxidizing archaea, the community composition of organisms responsible for production and consumption of nitrous oxide was altered under nutrient enrichment. These results suggest that elevated rates of nitrous oxide production and consumption are the result of changes in community structure, not simply changes in microbial activity.
2018-01-13 | GSE108888 | GEO
Project description:Functional redundancy in bacterial communities is expected to allow microbial assemblages to survive perturbation by allowing continuity in function despite compositional changes in communities. Recent evidence suggests, however, that microbial communities change both composition and function as a result of disturbance. We present evidence for a third response: resistance. We examined microbial community response to perturbation caused by nutrient enrichment in salt marsh sediments using deep pyrosequencing of 16S rRNA and functional gene microarrays targeting the nirS gene. Composition of the microbial community, as demonstrated by both genes, was unaffected by significant variations in external nutrient supply, despite demonstrable and diverse nutrient–induced changes in many aspects of marsh ecology. The lack of response to external forcing demonstrates a remarkable uncoupling between microbial composition and ecosystem-level biogeochemical processes and suggests that sediment microbial communities are able to resist some forms of perturbation. nirS gene diversity from two salt marsh experiments, GSM (4 treatments, 8 samples, duplicate arrays, four replicate blocks per array, 8 arrays per slide) and PIE (2 treatments, 16 samples, duplicate arrays four replicate blocks per array, 8 arrays per slide)
2010-11-13 | E-GEOD-25227 | biostudies-arrayexpress
Project description:Salt marshes sediment microhabitats Metagenome
| PRJNA236470 | ENA
Project description:<p>Salt marshes are highly productive ecosystems where microbial communities drive key</p><p>transformations of organic matter at rates often exceeding those of oceanic and inland</p><p>environments. Viruses are recognised as important drivers and regulators of global</p><p>biogeochemical cycling, yet their diversity, host range, and functional roles in salt</p><p>marsh ecosystems remain largely unresolved. To address these gaps, we investigated</p><p>how viral lysis and host reprogramming can affect microbe-mediated organic matter</p><p>transformations in a salt marsh of the Venice lagoon (Italy). Focusing on tidal creek</p><p>surface sediments, we reconstructed 311 metagenome-assembled genomes (MAGs),</p><p>built corresponding genome-scale metabolic models (GEMs) individually constrained</p><p>with 121 metabolites detected in the sediments, and identified 3,537 viral populations</p><p>(vOTUs) across 10 samples. To assess the impact of viral lysis, we inferred prokaryotic</p><p>hosts for 243 vOTUs and analysed host metabolism through MAG pathway analysis</p><p>and GEM flux modelling across 13 bacterial orders, thus highlighting a negative impact</p><p>on polysaccharide degradation, organic nitrogen mineralisation, and organosulphur</p><p>mineralisation/volatilisation processes. For host metabolic reprogramming, we</p><p>characterised a subset of 50 auxiliary viral genes (AVGs) by mapping them to GEM</p><p>reactions and analysing their stoichiometry, directionality, and pathway context,</p><p>outlining two dominant strategies: resource scavenging through nucleotide-sugar</p><p>biosynthesis, amino acid utilisation, and sulphate assimilation; functional host</p><p>maintenance through cofactor biosynthesis, electron transport, and energy production</p><p>through carbonyl-compound utilisation. Our findings provide a mechanistic view of the</p><p>viral influence on organic matter transformations in salt marsh sediments and confirm</p><p>viruses as key players in salt marsh biogeochemistry.</p>
2026-06-26 | MTBLS12630 | MetaboLights
Project description:srb of salt marshes Targeted loci environmental
| PRJNA304076 | ENA