{"type": "FeatureCollection", "features": [{"id": "10.1007/s10705-013-9591-8", "type": "Feature", "geometry": null, "properties": {"license": "Closed Access", "updated": "2026-09-20T16:14:38Z", "type": "Journal Article", "created": "2013-12-07", "title": "Contribution Of Relay Intercropping With Legume Cover Crops On Nitrogen Dynamics In Organic Grain Systems", "description": "Nitrogen (N) management is a key issue in livestock-free organic grain systems. Relay intercropping with a legume cover crop can be a useful technique for improving N availability when two cash crops are grown successively. We evaluated the benefits of four relay intercropped legumes (Medicago lupulina, Medicago sativa, Trifolium pratense and Trifolium repens) on N dynamics and their contribution to the associated and subsequent cash crops in six fields of organic farms located in South-East France. None of the relay intercropped legumes affected the N uptake of the associated winter wheat but all significantly increased the N uptake of the succeeding spring crop, either maize or spring wheat. The improvement of the N nutrition of the subsequent maize crop induced a 30 % increase in grain yield. All relay intercropped legumes enriched the soil-plant system in N through symbiotic fixation. From 71 to 96 % of the N contained in the shoots of the legumes in late autumn was derived from the atmosphere (Ndfa) and varied between 38 and 67 kg Ndfa ha(-1). Even if the cover crop is expected to limit N leaching during wintertime, the presence of relay intercropped legumes had no significant effect on N leaching during winter compared to the control.", "keywords": ["[SDV.SA]Life Sciences [q-bio]/Agricultural sciences", "2. Zero hunger", "0106 biological sciences", "winter-wheat", "[SDV.SA] Life Sciences [q-bio]/Agricultural sciences", "corn following wheat", "Legume cover crop", "Organic farming", "N uptake", "agricultural system", "natural-abundance", "04 agricultural and veterinary sciences", "15. Life on land", "Nitrate", "01 natural sciences", "630", "Relay intercropping", "n-2 fixation", "undersown crop", "catch crop", "Leaching", "isotopic fractionation", "rhizobial strain", "0401 agriculture", " forestry", " and fisheries", "living mulche"]}, "links": [{"href": "https://doi.org/10.1007/s10705-013-9591-8"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Nutrient%20Cycling%20in%20Agroecosystems", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1007/s10705-013-9591-8", "name": "item", "description": "10.1007/s10705-013-9591-8", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1007/s10705-013-9591-8"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2013-12-08T00:00:00Z"}}, {"id": "10.1111/1462-2920.13954", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:17:25Z", "type": "Journal Article", "created": "2022-10-18", "title": "Application of stable-isotope labelling techniques for the detection of active diazotrophs", "description": "Summary<p>Investigating active participants in the fixation of dinitrogen gas is vital as N is often a limiting factor for primary production. Biological nitrogen fixation is performed by a diverse guild of bacteria and archaea (diazotrophs), which can be free\uffe2\uff80\uff90living or symbionts. Free\uffe2\uff80\uff90living diazotrophs are widely distributed in the environment, yet our knowledge about their identity and ecophysiology is still limited. A major challenge in investigating this guild is inferring activity from genetic data as this process is highly regulated. To address this challenge, we evaluated and improved several 15N\uffe2\uff80\uff90based methods for detecting N2 fixation activity (with a focus on soil samples) and studying active diazotrophs. We compared the acetylene reduction assay and the 15N2 tracer method and demonstrated that the latter is more sensitive in samples with low activity. Additionally, tracing 15N into microbial RNA provides much higher sensitivity compared to bulk soil analysis. Active soil diazotrophs were identified with a 15N\uffe2\uff80\uff90RNA\uffe2\uff80\uff90SIP approach optimized for environmental samples and benchmarked to 15N\uffe2\uff80\uff90DNA\uffe2\uff80\uff90SIP. Lastly, we investigated the feasibility of using SIP\uffe2\uff80\uff90Raman microspectroscopy for detecting 15N\uffe2\uff80\uff90labelled cells. Taken together, these tools allow identifying and investigating active free\uffe2\uff80\uff90living diazotrophs in a highly sensitive manner in diverse environments, from bulk to the single\uffe2\uff80\uff90cell level.</p>", "keywords": ["Spectrum Analysis", " Raman", "BIOLOGICAL SOIL CRUSTS", "106005 Bioinformatik", "106023 Molekularbiologie", "Nitrogen Fixation", "REVEALS", "FLUORESCENCE", "Research Articles", "Soil Microbiology", "106022 Mikrobiologie", "SPECTROSCOPY", "Bacteria", "Nitrogen Isotopes", "106003 Biodiversity research", "106023 Molecular biology", "GENETIC-REGULATION", "Archaea", "6. Clean water", "SURFACE-ENHANCED RAMAN", "COMMUNITY", "106003 Biodiversit\u00e4tsforschung", "13. Climate action", "Isotope Labeling", "106022 Microbiology", "NITROGEN-FIXATION", "106005 Bioinformatics", "RIBOSOMAL-RNA", "N-2 FIXATION"]}, "links": [{"href": "https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.13954"}, {"href": "https://doi.org/10.1111/1462-2920.13954"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/1462-2920.13954", "name": "item", "description": "10.1111/1462-2920.13954", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/1462-2920.13954"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-12-15T00:00:00Z"}}, {"id": "10.1093/jxb/erq249", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:17:16Z", "type": "Journal Article", "created": "2010-08-27", "title": "Plant Physiology And Proteomics Reveals The Leaf Response To Drought In Alfalfa (Medicago Sativa L.)", "description": "Despite its relevance, protein regulation, metabolic adjustment, and the physiological status of plants under drought is not well understood in relation to the role of nitrogen fixation in nodules. In this study, nodulated alfalfa plants were exposed to drought conditions. The study determined the physiological, metabolic, and proteomic processes involved in photosynthetic inhibition in relation to the decrease in nitrogenase (N(ase)) activity. The deleterious effect of drought on alfalfa performance was targeted towards photosynthesis and N(ase) activity. At the leaf level, photosynthetic inhibition was mainly caused by the inhibition of Rubisco. The proteomic profile and physiological measurements revealed that the reduced carboxylation capacity of droughted plants was related to limitations in Rubisco protein content, activation state, and RuBP regeneration. Drought also decreased amino acid content such as asparagine, and glutamic acid, and Rubisco protein content indicating that N availability limitations were caused by N(ase) activity inhibition. In this context, drought induced the decrease in Rubisco binding protein content at the leaf level and proteases were up-regulated so as to degrade Rubisco protein. This degradation enabled the reallocation of the Rubisco-derived N to the synthesis of amino acids with osmoregulant capacity. Rubisco degradation under drought conditions was induced so as to remobilize Rubisco-derived N to compensate for the decrease in N associated with N(ase) inhibition. Metabolic analyses showed that droughted plants increased amino acid (proline, a major compound involved in osmotic regulation) and soluble sugar (D-pinitol) levels to contribute towards the decrease in osmotic potential (\u03a8(s)). At the nodule level, drought had an inhibitory effect on N(ase) activity. This decrease in N(ase) activity was not induced by substrate shortage, as reflected by an increase in total soluble sugars (TSS) in the nodules. Proline accumulation in the nodule could also be associated with an osmoregulatory response to drought and might function as a protective agent against ROS. In droughted nodules, the decrease in N(2) fixation was caused by an increase in oxygen resistance that was induced in the nodule. This was a mechanism to avoid oxidative damage associated with reduced respiration activity and the consequent increase in oxygen content. This study highlighted that even though drought had a direct effect on leaves, the deleterious effects of drought on nodules also conditioned leaf responsiveness.", "keywords": ["Proteomics", "0301 basic medicine", "570", "Rubisco", "Proteome", "[SDV]Life Sciences [q-bio]", "proteome", "N-2 FIXATION RESPONSE", "drought", "N2 fixation", "03 medical and health sciences", "XANTHOPHYLL CYCLE", "N-2 fixation", "2-CYSTEINE PEROXIREDOXIN", "Nitrogenase", "oxidative stress", "AMINO-ACIDS", "Photosynthesis", "climate", "agriculture", "Plant Proteins", "580", "N remobilization", "2. Zero hunger", "0303 health sciences", "photosynthesis", "PINITOL ACCUMULATION", "Drought", "RIBULOSE-1", "5-BISPHOSPHATE CARBOXYLASE-OXYGENASE", "Water", "BRASSICA-NAPUS", "N(O)-TERT-BUTYLDIMETHYLSILYL DERIVATIVES", "15. Life on land", "Research Papers", "6. Clean water", "Droughts", "[SDV] Life Sciences [q-bio]", "Plant Leaves", "nitrogen fixation", "Oxidative stress", "rubisco", "NITROGEN-FIXATION", "WATER-WATER CYCLE", "Medicago sativa"]}, "links": [{"href": "https://doi.org/10.1093/jxb/erq249"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Journal%20of%20Experimental%20Botany", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1093/jxb/erq249", "name": "item", "description": "10.1093/jxb/erq249", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1093/jxb/erq249"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2010-08-25T00:00:00Z"}}, {"id": "10.1111/1462-2920.16213", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:17:25Z", "type": "Journal Article", "created": "2022-10-18", "title": "Application of stable\u2010isotope labelling techniques for the detection of active diazotrophs", "description": "Summary<p>Investigating active participants in the fixation of dinitrogen gas is vital as N is often a limiting factor for primary production. Biological nitrogen fixation is performed by a diverse guild of bacteria and archaea (diazotrophs), which can be free\uffe2\uff80\uff90living or symbionts. Free\uffe2\uff80\uff90living diazotrophs are widely distributed in the environment, yet our knowledge about their identity and ecophysiology is still limited. A major challenge in investigating this guild is inferring activity from genetic data as this process is highly regulated. To address this challenge, we evaluated and improved several 15N\uffe2\uff80\uff90based methods for detecting N2 fixation activity (with a focus on soil samples) and studying active diazotrophs. We compared the acetylene reduction assay and the 15N2 tracer method and demonstrated that the latter is more sensitive in samples with low activity. Additionally, tracing 15N into microbial RNA provides much higher sensitivity compared to bulk soil analysis. Active soil diazotrophs were identified with a 15N\uffe2\uff80\uff90RNA\uffe2\uff80\uff90SIP approach optimized for environmental samples and benchmarked to 15N\uffe2\uff80\uff90DNA\uffe2\uff80\uff90SIP. Lastly, we investigated the feasibility of using SIP\uffe2\uff80\uff90Raman microspectroscopy for detecting 15N\uffe2\uff80\uff90labelled cells. Taken together, these tools allow identifying and investigating active free\uffe2\uff80\uff90living diazotrophs in a highly sensitive manner in diverse environments, from bulk to the single\uffe2\uff80\uff90cell level.</p", "keywords": ["Spectrum Analysis", " Raman", "BIOLOGICAL SOIL CRUSTS", "106005 Bioinformatik", "106023 Molekularbiologie", "Nitrogen Fixation", "REVEALS", "FLUORESCENCE", "Research Articles", "Soil Microbiology", "106022 Mikrobiologie", "SPECTROSCOPY", "Bacteria", "Nitrogen Isotopes", "106003 Biodiversity research", "106023 Molecular biology", "GENETIC-REGULATION", "Archaea", "6. Clean water", "SURFACE-ENHANCED RAMAN", "COMMUNITY", "106003 Biodiversit\u00e4tsforschung", "13. Climate action", "Isotope Labeling", "106022 Microbiology", "NITROGEN-FIXATION", "106005 Bioinformatics", "RIBOSOMAL-RNA", "N-2 FIXATION"]}, "links": [{"href": "https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.13954"}, {"href": "https://doi.org/10.1111/1462-2920.16213"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.1111/1462-2920.16213", "name": "item", "description": "10.1111/1462-2920.16213", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.1111/1462-2920.16213"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-12-15T00:00:00Z"}}, {"id": "10.3389/fmicb.2018.00703", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-09-20T16:18:57Z", "type": "Journal Article", "created": "2018-04-30", "title": "Evaluation of primers targeting the diazotroph functional gene and development of NifMAP \u2013 a bioinformatics pipeline for analyzing nifH amplicon data", "description": "Diazotrophic microorganisms introduce biologically available nitrogen (N) to the global N cycle through the activity of the nitrogenase enzyme. The genetically conserved dinitrogenase reductase (nifH) gene is phylogenetically distributed across four clusters (I-IV) and is widely used as a marker gene for N2 fixation, permitting investigators to study the genetic diversity of diazotrophs in nature and target potential participants in N2 fixation. To date there have been limited, standardized pipelines for analyzing the nifH functional gene, which is in stark contrast to the 16S rRNA gene. Here we present a bioinformatics pipeline for processing nifH amplicon datasets - NifMAP ('NifH MiSeq Illumina Amplicon Analysis Pipeline'), which as a novel aspect uses Hidden-Markov Models to filter out homologous genes to nifH. By using this pipeline, we evaluated the broadly inclusive primer pairs (Ueda19F-R6, IGK3-DVV, and F2-R6) that target the nifH gene. To evaluate any systematic biases, the nifH gene was amplified with the aforementioned primer pairs in a diverse collection of environmental samples (soils, rhizosphere and roots samples, biological soil crusts and estuarine samples), in addition to a nifH mock community consisting of six phylogenetically diverse members. We noted that all primer pairs co-amplified nifH homologs to varying degrees; up to 90% of the amplicons were nifH homologs with IGK3-DVV in some samples (rhizosphere and roots from tall oat-grass). In regards to specificity, we observed some degree of bias across the primer pairs. For example, primer pair F2-R6 discriminated against cyanobacteria (amongst others), yet captured many sequences from subclusters IIIE and IIIL-N. These aforementioned subclusters were largely missing by the primer pair IGK3-DVV, which also tended to discriminate against Alphaproteobacteria, but amplified sequences within clusters IIIC (affiliated with Clostridia) and clusters IVB and IVC. Primer pair Ueda19F-R6 exhibited the least bias and successfully captured diazotrophs in cluster I and subclusters IIIE, IIIL, IIIM, and IIIN, but tended to discriminate against Firmicutes and subcluster IIIC. Taken together, our newly established bioinformatics pipeline, NifMAP, along with our systematic evaluations of nifH primer pairs permit more robust, high-throughput investigations of diazotrophs in diverse environments.", "keywords": ["0301 basic medicine", "DIVERSITY", "nifH gene", "Microbiology", "03 medical and health sciences", "NifMAP", "Nitrogen fixation", "PARTICULATE METHANE MONOOXYGENASE", "MOLYBDENUM-NITROGENASE", "Primer evaluation", "MICROORGANISMS", "NifH gene", "2. Zero hunger", "106022 Mikrobiologie", "0303 health sciences", "SEQUENCES", "GROUP-IV NITROGENASE", "AMPLIFICATION", "PERFORMANCE", "QR1-502", "primer evaluation", "nitrogen fixation", "106022 Microbiology", "COMMUNITIES", "N-2 FIXATION", "Illumina amplicon sequencing"]}, "links": [{"href": "https://doi.org/10.3389/fmicb.2018.00703"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "10.3389/fmicb.2018.00703", "name": "item", "description": "10.3389/fmicb.2018.00703", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/10.3389/fmicb.2018.00703"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-04-30T00:00:00Z"}}, {"id": "11353/10.1033274", "type": "Feature", "geometry": null, "properties": {"license": "Open Access", "updated": "2026-09-20T16:21:54Z", "type": "Journal Article", "created": "2018-04-30", "title": "Evaluation of Primers Targeting the Diazotroph Functional Gene and Development of NifMAP \u2013 A Bioinformatics Pipeline for Analyzing nifH Amplicon Data", "description": "Diazotrophic microorganisms introduce biologically available nitrogen (N) to the global N cycle through the activity of the nitrogenase enzyme. The genetically conserved dinitrogenase reductase (nifH) gene is phylogenetically distributed across four clusters (I-IV) and is widely used as a marker gene for N2 fixation, permitting investigators to study the genetic diversity of diazotrophs in nature and target potential participants in N2 fixation. To date there have been limited, standardized pipelines for analyzing the nifH functional gene, which is in stark contrast to the 16S rRNA gene. Here we present a bioinformatics pipeline for processing nifH amplicon datasets - NifMAP ('NifH MiSeq Illumina Amplicon Analysis Pipeline'), which as a novel aspect uses Hidden-Markov Models to filter out homologous genes to nifH. By using this pipeline, we evaluated the broadly inclusive primer pairs (Ueda19F-R6, IGK3-DVV, and F2-R6) that target the nifH gene. To evaluate any systematic biases, the nifH gene was amplified with the aforementioned primer pairs in a diverse collection of environmental samples (soils, rhizosphere and roots samples, biological soil crusts and estuarine samples), in addition to a nifH mock community consisting of six phylogenetically diverse members. We noted that all primer pairs co-amplified nifH homologs to varying degrees; up to 90% of the amplicons were nifH homologs with IGK3-DVV in some samples (rhizosphere and roots from tall oat-grass). In regards to specificity, we observed some degree of bias across the primer pairs. For example, primer pair F2-R6 discriminated against cyanobacteria (amongst others), yet captured many sequences from subclusters IIIE and IIIL-N. These aforementioned subclusters were largely missing by the primer pair IGK3-DVV, which also tended to discriminate against Alphaproteobacteria, but amplified sequences within clusters IIIC (affiliated with Clostridia) and clusters IVB and IVC. Primer pair Ueda19F-R6 exhibited the least bias and successfully captured diazotrophs in cluster I and subclusters IIIE, IIIL, IIIM, and IIIN, but tended to discriminate against Firmicutes and subcluster IIIC. Taken together, our newly established bioinformatics pipeline, NifMAP, along with our systematic evaluations of nifH primer pairs permit more robust, high-throughput investigations of diazotrophs in diverse environments.", "keywords": ["0301 basic medicine", "DIVERSITY", "nifH gene", "Microbiology", "03 medical and health sciences", "NifMAP", "Nitrogen fixation", "PARTICULATE METHANE MONOOXYGENASE", "MOLYBDENUM-NITROGENASE", "Primer evaluation", "MICROORGANISMS", "NifH gene", "2. Zero hunger", "106022 Mikrobiologie", "0303 health sciences", "SEQUENCES", "GROUP-IV NITROGENASE", "AMPLIFICATION", "PERFORMANCE", "16. Peace & justice", "QR1-502", "primer evaluation", "nitrogen fixation", "106022 Microbiology", "COMMUNITIES", "N-2 FIXATION", "Illumina amplicon sequencing"]}, "links": [{"href": "https://doi.org/11353/10.1033274"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Frontiers%20in%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "11353/10.1033274", "name": "item", "description": "11353/10.1033274", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/11353/10.1033274"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2018-04-30T00:00:00Z"}}, {"id": "2764305888", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:22:31Z", "type": "Journal Article", "created": "2022-10-18", "title": "Application of stable\u2010isotope labelling techniques for the detection of active diazotrophs", "description": "Summary<p>Investigating active participants in the fixation of dinitrogen gas is vital as N is often a limiting factor for primary production. Biological nitrogen fixation is performed by a diverse guild of bacteria and archaea (diazotrophs), which can be free\uffe2\uff80\uff90living or symbionts. Free\uffe2\uff80\uff90living diazotrophs are widely distributed in the environment, yet our knowledge about their identity and ecophysiology is still limited. A major challenge in investigating this guild is inferring activity from genetic data as this process is highly regulated. To address this challenge, we evaluated and improved several 15N\uffe2\uff80\uff90based methods for detecting N2 fixation activity (with a focus on soil samples) and studying active diazotrophs. We compared the acetylene reduction assay and the 15N2 tracer method and demonstrated that the latter is more sensitive in samples with low activity. Additionally, tracing 15N into microbial RNA provides much higher sensitivity compared to bulk soil analysis. Active soil diazotrophs were identified with a 15N\uffe2\uff80\uff90RNA\uffe2\uff80\uff90SIP approach optimized for environmental samples and benchmarked to 15N\uffe2\uff80\uff90DNA\uffe2\uff80\uff90SIP. Lastly, we investigated the feasibility of using SIP\uffe2\uff80\uff90Raman microspectroscopy for detecting 15N\uffe2\uff80\uff90labelled cells. Taken together, these tools allow identifying and investigating active free\uffe2\uff80\uff90living diazotrophs in a highly sensitive manner in diverse environments, from bulk to the single\uffe2\uff80\uff90cell level.</p", "keywords": ["Spectrum Analysis", " Raman", "BIOLOGICAL SOIL CRUSTS", "106005 Bioinformatik", "106023 Molekularbiologie", "Nitrogen Fixation", "REVEALS", "FLUORESCENCE", "Research Articles", "Soil Microbiology", "106022 Mikrobiologie", "SPECTROSCOPY", "Bacteria", "Nitrogen Isotopes", "106003 Biodiversity research", "106023 Molecular biology", "GENETIC-REGULATION", "Archaea", "6. Clean water", "SURFACE-ENHANCED RAMAN", "COMMUNITY", "106003 Biodiversit\u00e4tsforschung", "13. Climate action", "Isotope Labeling", "106022 Microbiology", "NITROGEN-FIXATION", "106005 Bioinformatics", "RIBOSOMAL-RNA", "N-2 FIXATION"]}, "links": [{"href": "https://onlinelibrary.wiley.com/doi/pdf/10.1111/1462-2920.13954"}, {"href": "https://doi.org/2764305888"}, {"rel": "related", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/Environmental%20Microbiology", "name": "related record", "description": "related record", "type": "application/json"}, {"rel": "self", "type": "application/geo+json", "title": "2764305888", "name": "item", "description": "2764305888", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main/items/2764305888"}, {"rel": "collection", "type": "application/json", "title": "Collection", "name": "collection", "description": "Collection", "href": "https://repository.soilwise-he.eu/cat/collections/metadata:main"}], "time": {"date": "2017-12-15T00:00:00Z"}}, {"id": "PMC5814836", "type": "Feature", "geometry": null, "properties": {"updated": "2026-09-20T16:24:22Z", "type": "Journal Article", "created": "2022-10-18", "title": "Application of stable\u2010isotope labelling techniques for the detection of active diazotrophs", "description": "Summary                   <p>                     Investigating active participants in the fixation of dinitrogen gas is vital as N is often a limiting factor for primary production. Biological nitrogen fixation is performed by a diverse guild of bacteria and archaea (diazotrophs), which can be free\uffe2\uff80\uff90living or symbionts. Free\uffe2\uff80\uff90living diazotrophs are widely distributed in the environment, yet our knowledge about their identity and ecophysiology is still limited. A major challenge in investigating this guild is inferring activity from genetic data as this process is highly regulated. To address this challenge, we evaluated and improved several                     15                     N\uffe2\uff80\uff90based methods for detecting N                     2                     fixation activity (with a focus on soil samples) and studying active diazotrophs. We compared the acetylene reduction assay and the                     15                     N                     2                     tracer method and demonstrated that the latter is more sensitive in samples with low activity. Additionally, tracing                     15                     N into microbial RNA provides much higher sensitivity compared to bulk soil analysis. Active soil diazotrophs were identified with a                     15                     N\uffe2\uff80\uff90RNA\uffe2\uff80\uff90SIP approach optimized for environmental samples and benchmarked to                     15                     N\uffe2\uff80\uff90DNA\uffe2\uff80\uff90SIP. Lastly, we investigated the feasibility of using SIP\uffe2\uff80\uff90Raman microspectroscopy for detecting                     15                     N\uffe2\uff80\uff90labelled cells. Taken together, these tools allow identifying and investigating active free\uffe2\uff80\uff90living diazotrophs in a highly sensitive manner in diverse environments, from bulk to the single\uffe2\uff80\uff90cell level.                   </p", "keywords": ["Spectrum Analysis", " Raman", "BIOLOGICAL SOIL CRUSTS", "106005 Bioinformatik", "106023 Molekularbiologie", "Nitrogen Fixation", "REVEALS", "FLUORESCENCE", "Research Articles", "Soil Microbiology", "106022 Mikrobiologie", "SPECTROSCOPY", "Bacteria", "Nitrogen Isotopes", "106003 Biodiversity research", "106023 Molecular biology", "GENETIC-REGULATION", "Archaea", "6. Clean water", "SURFACE-ENHANCED RAMAN", "COMMUNITY", "106003 Biodiversit\u00e4tsforschung", "13. 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