Marine metagenome
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA244725 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR1251987.fastq.gz | Fastqsanger.gz |
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Project description:Bacterial community composition in the naturally iron-fertilized region off Kerguelen Island (Southern Ocean). Targeted Locus (Loci)
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Project description:Iron and light are typically recognized as major limiting factors controlling phytoplankton growth in the Southern Ocean. Recent field-based evidence suggests, however, that manganese concentrations in this region can be low enough to impact phytoplankton physiology and primary productivity. Our study examined the interactive influence of combined iron and manganese deprivation on protein expression and photophysiology in Phaeocystis antarctica, a key Antarctic phytoplankter, and provide taxon-specific proteomic evidence that natural Southern Ocean Phaeocystis populations regularly experience stress due to combined low manganese and iron availability. In culture, combined low iron and manganese induced large scale changes in the Phaeocystis proteome and resulted in reorganization of key components of the photosynthetic apparatus; these differences were largely distinct from those arising from changes in irradiance. These results implicate manganese availability as an important driver of Southern Ocean productivity and demonstrate the utility of peptide mass spectrometry as a tool for mapping of manganese contributions to HNLC conditions in this region.
2019-06-25 | PXD010974 | Pride
Project description:Coastal Antarctic marine ecosystems play an important role in carbon cycling due to their highly productive seasonal phytoplankton blooms. Southern Ocean microbes are primarily limited by light and iron (Fe) and can be co-limited by cobalamin (vitamin B12 ). Micronutrient limitation is a key driver of ecosystem dynamics and influences the composition of blooms, which are often dominated by either diatoms or the haptophyte Phaeocystis antarctica, each with varied impacts on carbon cycling. However, the vitamin requirements and ecophysiology of the keystone species P. antarctica remains poorly characterized. Using cultures, physiological analysis, and comparative ’omics we examined the response of P. antarctica to a matrix of Fe-B12 conditions. We show that P. antarctica is not auxotrophic for B12 , as previously suggested, and report new mechanistic insights of its B12 response in cultures of predominantly solitary and colonial cells. Proteomics coupled with proteogenomics detected a B12 -independent methionine synthase fusion protein (MetE-fusion) that is expressed under vitamin limitation and is interreplaced with the B12 -dependent isoform (MetH) in replete conditions. Database searches returned homologs of the MetE-fusion protein in multiple Phaeocystis species and in a wide range of marine microbes, including other photosynthetic eukaryotes with polymorphic life cycles and also bacterioplankton. Furthermore, MetE-fusion homologs were found to be expressed in metaproteomic and metatranscriptomic field samples in polar and more geographically widespread regions. As climate change impacts micronutrient availability in the coastal Southern Ocean, our finding that P. antarctica has a flexible B12 metabolism has implications for its relative fitness compared to B12 -auxotrophic diatoms.
2023-02-27 | PXD031524 | Pride
Project description:Projected responses of ocean net primary productivity (NPP) to climate change are highly uncertain. The climate sensitivity of phytoplankton nutrient limitation in the low-latitude Pacific plays a crucial role, but field measurements are insufficient to provide suitable constraints. Here we quantify two decades of nutrient limitation in the Equatorial Pacific with satellite observations. Using field nutrient addition experiments, proteomics, and above-water hyperspectral radiometry, we demonstrate that physiological responses of phytoplankton to iron limitation led to ~3-fold increases in chlorophyll-normalized phytoplankton fluorescence. Extension to the >18-year satellite fluorescence record showed that Equatorial Pacific iron limitation was robust to changes in physical forcing through multiple El Niño–Southern Oscillation cycles, despite coherent fluctuations in limitation strength. In contrast, these iron limitation changes were overestimated 2-fold by a state-of-the-art climate model. Such synoptic constraints provide a powerful new approach for benchmarking the realism of model NPP projections to climate changes.
2023-06-26 | PXD030610 | Pride
Project description:We performed RNA-sequencing experiments to examine the differential regulation of genes in the genome of the Southern Ocean diatom Fragilariopsis cylindrus including diverged alleles. RNA-seq was performed on three replicate samples for each experimental condition. Phytoplankton cells were grown under six different experimental conditions including (1) optimal growth, (2) freezing temperatures, (3) elevated temperature, (4) elevated carbon dioxide concentrations, (5) low iron concentrations and (6) prolonged darkness. Total RNA was extracted using a guanidinium thiocyanate-phenol-chloroform extraction protocol, followed by DNase I treatment and RNA purification (Quiagen). First strand cDNA synthesis was performed using random hexamers. Library preparation was performed using the RNA-seq Sample Prep Kit (Illumina) and sequencing was conducted according to the TruSeq RNA sequencing protocol (Illumina) All samples were sequenced together in one flowcell on one lane.
2016-12-16 | E-MTAB-5024 | biostudies-arrayexpress
Project description:Marine microalgae (phytoplankton) mediate almost half of the worldwide photosynthetic carbon dioxide fixation and therefore play a pivotal role in global carbon cycling, most prominently during massive phytoplankton blooms. Phytoplankton biomass consists of considerable proportions of polysaccharides, substantial parts of which are rapidly remineralized by heterotrophic bacteria. We analyzed the diversity, activity and functional potential of such polysaccharide-degrading bacteria in different size fractions during a diverse spring phytoplankton bloom at Helgoland Roads (southern North Sea) at high temporal resolution using microscopic, physicochemical, biodiversity, metagenome and metaproteome analyses.
2024-01-15 | PXD046705 | Pride
Project description:Prokaryotic diversity in the Southern Ocean (Kerguelen Region)
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Project description:In summer 2014, we conducted experiments to determine the effects of different N substrates on phytoplankton communities in the North Pacific Ocean and in the transition zone of the California Current and gyre (Shilova, Mills et al., 2017). Samples were incubated with nitrate, ammonium, urea, and filtered deep water (FDW) for 48 hours (T48). Two treatments added iron, alone (Fe) or with a mix of N substrates (N+Fe), to determine the effects of Fe on the utilization of N substrates. All treatments resulted in changes in phytoplankton cell abundances and photosynthetic activity at both locations, with differences between phytoplankton groups. Prochlorococcus had large increases in biomass in response to ammonium and urea, while both eukaryotic phytoplankton and Synechococcus had only modest biomass increases in response to N+Fe and FDW. Moreover, distinct physiological responses were observed within sub-populations of Prochlorococcus and Synechococcus. In order to understand the variable responses to N substrates among phytoplankton groups and sub-populations in the California Current transition zone, the present work examines transcriptional changes that occurred 24 h after the substrates were added. Specifically, we hypothesize that transcription changes at 24 h indicate which phytoplankton taxa are N-limited, and thus help explain changes in cell abundances and photosynthetic activity by individual phytoplankton groups observed at 48 h. Furthermore, we hypothesize that the diversity in physiological responses within Prochlorococcus and Synechococcus are evident in the transcriptional responses measured at sub-population resolution.
2020-04-12 | GSE130464 | GEO
Project description:Samples were taken from surface, 150m and 350m depth in HNLS waters and waters off the coast of Kerguelen Island in the Indian sector of the Southern Ocean during the Soclim cruise in November 2016. Environmental samples were taken and filtered according to protocol. Using SDS page proteins were extracted and purified. For proteomic analysis, technical replicates (derived from two separate MS/MS runs) were combined.
2023-01-10 | MSV000091034 | MassIVE
Project description:Samples were taken from surface, 150m and 350m depth in HNLS waters and waters off the coast of Kerguelen Island in the Indian sector of the Southern Ocean during the Mobydick cruise in Feb/March 2018. Environmental samples were taken and filtered according to protocol. Using SDS page proteins were extracted and purified. For proteomic analysis, technical replicates (derived from two separate MS/MS runs) were combined.
2023-01-10 | MSV000091032 | MassIVE