Canadian Streams
Ontology highlight
ABSTRACT:
PROVIDER: PRJEB34059 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:Measure changes in dissolved organic matter composition and resulting microbial decomposition rates in an experimentally warmed peatland.
2021-05-27 | PXD019912 | Pride
Project description:When jellyfish blooms decay, sinking jellyfish detrital organic matter (jelly-OM), rich in proteins and characterized by a low C : N ratio, becomes a significant source of OM for marine microorganisms. Yet, the key players and the process of microbial jelly-OM degradation and the consequences for marine ecosystems remain unclear. We simulated the scenario potentially experienced by the coastal pelagic microbiome after the decay of a bloom of the cosmopolitan Aurelia aurita s.l.. We show that about half of the jelly-OM is instantly available as dissolved organic matter and thus, exclusively and readily accessible to microbes. During a typical decay of an A. aurita bloom in the northern Adriatic Sea about 100 mg of jelly-OM L-1 becomes available, about 44 µmol L-1 as dissolved organic carbon (DOC), 13 µmol L-1 as total dissolved nitrogen, 11 µmol L-1 of total hydrolysable dissolved amino acids (THDAA) and 0.6 µmol L-1 PO43-. The labile jelly-OM was degraded within 1.5 days (> 98% of proteins, ~ 70% of THDAA (and within ~97% of DFAA) and entire DOC pool) by a consortium of Pseudoalteromonas, Alteromonas and Vibrio. These bacteria accounted for > 90% of all metabolically active jelly-OM degraders, exhibiting high bacterial growth efficiencies. This implies that a major fraction of the detrital jelly-OM is rapidly incorporated into biomass by opportunistic bacteria. Microbial processing of jelly-OM resulted in the accumulation of DON compounds (within some DFAA species, but mostly DCAA) and inorganic nutrients, with possible implications for biogeochemical cycles.
2021-09-07 | PXD021342 | JPOST Repository
Project description:Prolific heterotrophic biofilm growth is a common occurrence in airport receiving streams containing deicer and anti-icer runoff. This study investigated relations of heterotrophic biofilm prevalence and community composition to environmental conditions at stream sites upstream and downstream of Milwaukee Mitchell International Airport in Milwaukee, WI, during two deicing seasons (2009–2010 and 2010–2011). Modern genetic tools (such as microarray) have not previously been applied to biofilm communities in this type of setting. We used microarray results to characterize biofilm community composition as well as the response of the biofilm community to environmental factors (i.e., organic content (using chemical oxygen demand concentration) and temperature).
2019-05-13 | GSE129990 | GEO
Project description:Many trees form ectomycorrhizal symbiosis with fungi. During symbiosis, the tree roots supply sugar to the fungi in exchange for nitrogen, and this process is critical for the nitrogen and carbon cycles in forest ecosystems. However, the extents to which ectomycorrhizal fungi can liberate nitrogen and modify the soil organic matter and the mechanisms by which they do so remain unclear since they have lost many enzymes for litter decomposition that were present in their free-living, saprotrophic ancestors. Using time-series spectroscopy and transcriptomics, we examined the ability of two ectomycorrhizal fungi from two independently evolved ectomycorrhizal lineages to mobilize soil organic nitrogen. Both species oxidized the organic matter and accessed the organic nitrogen. The expression of those events was controlled by the availability of glucose and inorganic nitrogen. Despite those similarities, the decomposition mechanisms, including the type of genes involved as well as the patterns of their expression, differed markedly between the two species. Our results suggest that in agreement with their diverse evolutionary origins, ectomycorrhizal fungi use different decomposition mechanisms to access organic nitrogen entrapped in soil organic matter. The timing and magnitude of the expression of the decomposition activity can be controlled by the below-ground nitrogen quality and the above-ground carbon supply.
2018-11-30 | GSE110485 | GEO
Project description:Decomposition of soil organic matter in forest soils is thought to be controlled by the activity of saprotrophic fungi, while biotrophic fungi including ectomycorrhizal fungi act as vectors for input of plant carbon. The limited decomposing ability of ectomycorrhizal fungi is supported by recent findings showing that they have lost many of the genes that encode hydrolytic plant cell-wall degrading enzymes in their saprophytic ancestors. Nevertheless, here we demonstrate that ectomycorrhizal fungi representing at least four origins of symbiosis have retained significant capacity to degrade humus-rich litter amended with glucose. Spectroscopy showed that this decomposition involves an oxidative mechanism and that the extent of oxidation varies with the phylogeny and ecology of the species. RNA-Seq analyses revealed that the genome-wide set of expressed transcripts during litter decomposition has diverged over evolutionary time. Each species expressed a unique set of enzymes that are involved in oxidative lignocellulose degradation by saprotrophic fungi. A comparison of closely related species within the Boletales showed that ectomycorrhizal fungi oxidized litter material as efficiently as brown-rot saprotrophs. The ectomycorrhizal species within this clade exhibited more similar decomposing mechanisms than expected from the species phylogeny in concordance with adaptive evolution occurring as a result of similar selection pressures. Our data shows that ectomycorrhizal fungi are potential organic matter decomposers, yet not saprotrophs. We suggest that the primary function of this decomposing activity is to mobilize nutrients embedded in organic matter complexes and that the activity is driven by host carbon supply. Comparative transcriptomics of ectomycorrhizal (ECM) versus brown-rot (BR) fungi while degrading soil-organic matter
2015-09-24 | E-GEOD-64897 | biostudies-arrayexpress
Project description:To study mixotrophy, it is desirable to have an organism capable of growth in the presence and absence of both organic and inorganic carbon sources, as well as organic and inorganic energy sources. Metallosphaera sedula is an extremely thermoacidophilic archaeon which has been shown to grow in the presence of inorganic carbon and energy source supplements (autotrophy), organic carbon and energy source supplements (heterotrophy), and in the presence of organic carbon and inorganic energy source supplements. The recent elucidation of M. sedula’s inorganic carbon fixation cycle and its genome sequence further facilitate its use in mixotrophic studies. In this study, we grow M. sedula heterotrophically in the presence of organic carbon and energy sources (0.1% tryptone), autotrophically in the presence of inorganic carbon and energy sources (H2 + CO2), and “mixotrophically” in the presence of both organic and inorganic carbon and energy sources (0.1% tryptone + H2 + CO2 ) to characterize the nature of mixotrophy exhibited.
2009-11-01 | GSE14978 | GEO
Project description:Small, biologically produced, organic molecules called metabolites play key roles in microbial systems where they directly mediate exchanges of nutrients, energy, and information. However, the study of dissolved polar metabolites in seawater and other environmental matrices has been hampered by analytical challenges including high inorganic ion concentrations, low analyte concentrations, and high chemical diversity. Here we show that a cation-exchange solid phase extraction (CX-SPE) sample preparation approach separates positively charged and zwitterionic metabolites from seawater and freshwater samples, allowing their analysis by liquid chromatography-mass spectrometry (LC-MS). We successfully extracted 69 known compounds from an in-house compound collection and evaluated the performance of the method by establishing extraction efficiencies and limits of detection (pM to low nM range) for these compounds. CX-SPE extracted a range of compounds including amino acids and compatible solutes, resulted in very low matrix effects, and performed robustly across large variations in salinity and dissolved organic matter (DOM) concentration. We compared CX-SPE to an established solid phase extraction procedure (PPL-SPE) and demonstrate that these two methods extract fundamentally different fractions of the dissolved metabolite pool with CX-SPE extracting compounds that are on average smaller and more polar. We use CX-SPE to analyze four environmental samples from distinct aquatic biomes, producing some of the first CX-SPE dissolved metabolomes. Quantified compounds ranged in concentration from 0.0093 nM to 49 nM and were composed primarily of amino acids (0.15 – 16 nM) and compatible solutes such as TMAO (0.89 – 49 nM) and glycine betaine (2.8 – 5.2 nM).
2022-08-30 | ST002292 | MetabolomicsWorkbench
Project description:Dissolved organic matter and leaf leachate incubations
2022-06-03 | MSV000089591 | MassIVE
Project description:Interlab study of marine dissolved organic matter and algae extracts.
2021-10-21 | MSV000088249 | MassIVE