Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"Diazotrophic"”.
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Multiscale, multiparadigm metabolic modeling of the keystone diazotrophic cyanobacterium, Trichodesmium erythraeum
… techniques while characterizing a crucial diazotrophic cyanobacterium, Trichodesmium erythraeum. It uses genome-scale modeling approaches to characterize a unique metabolism at the center of the carbon, nitrogen, and phosphorus biogeochemical cycles. It ties these models to experimentation, …
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Controls on nitrogen fixation and nitrogen release in a diazotrophic endosymbiont of shipworms
… is tightly regulated by oxygen in most other diazotrophic microbes. Also, the direct evidence of new N being incorporated into the host tissue indicates that there are potentially complex nutrient cycles in this symbiosis, which have not been investigated. We used the cultivated symbiont …
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Analysis of the Potential for Diazotrophic Endophytes to Increase Efficiency of Bioenergy Crop Production: Growth promotion effects of the endophytes isolated from Populus trichocarpa and Salix sitchensis
<bold>Analysis of the Potential for Diazotrophic Endophytes to Increase Efficiency of Bioenergy Crop Production: Growth promotion effects of the endophytes isolated from Populus trichocarpa and Salix sitchensis</bold> Jenny L. Knoth Chair of the Supervisory Committee: Associate Professor, Dr. …
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Impacts of Microenvironment On Distributions and Activities of Bacteria In A Salt Marsh Environment
… and seasonally non-responsive nitrogen fixing (diazotrophic) bacterial assemblages. Vibrionaceae are represented as members of the diazotrophically-active, seasonally non-responsive assemblage, indicating that this bacterial family is also a ubiquitous and potentially important component of the …
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Site-directed mutagenesis of the nitrogenase MoFe protein from Azotobacter vinelandii
… Ser substituted for Cys88 are still capable of diazotrophic growth (Nif+), though whole cell and crude extract acetylene reduction activity is lowered. Several substitutions (Cys, Asp, Phe, Asn, Met, Tyr, Leu) are tolerated at the His83 position, these Nif+ mutant strains also have varying …
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Exploring the Spatial Distribution of Marine Nitrogen Fixation Through Statistical Modeling, High-Resolution Observations and Molecular Level Characterization
… at a global scale. In contrast, individual diazotrophic phylotypes showed distinct relations to environmental properties. Machine learning methods including random forest (RF) and support vector regression (SVR) simulated the observed N2 fixation and diazotrophs fairly well by accounting for …
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Pseudomonas spp. Isolated from the Soybean Nodule Interior Promote Soybean Growth upon Field Amendment
Diazotrophic microbes reside in soybean nodules; however, other non-nitrogen fixing bacteria are a part of the interior nodule microbiome. Results from a previous greenhouse study show that a novel species of Pseudomonas associates with soybean nodules as a plant-growth promoting rhizobacteria …
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Nutritional contribution of atmospheric deposition to the Strandveld vegetation of West Coast South Africa Justine Muhoro Nyaga.
… deposition. Symbiotic and free-living diazotrophic bacteria and blue green algae also contribute N. In ecosystems with limited occurrence of N₂-fixation and occurring on low-nutrient bedrock, atmospheric deposition is the most significant source of nutrients. Nutrients from atmospheric …
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The Endophytes of Pediomelum Esculentum: A Unique Case in Legume Evolution
… fixation. We have investigated the presence of diazotrophic endophytes in <em>P. esculentum</em>. Bacteria were isolated from wild plants on nitrogen free media, identified with their partial <em>16S rRNA</em> gene sequences, and screened for the presence of the nitrogen fixation gene …
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Diversity of Free-living Nitrogen Fixing Bacteria in the Badlands of South Dakota
… the first known report of a Streptomyces that is diazotrophic, other than the thermophilic, autotrophic S. thermoautotrophicus. The nifH genes of these Streptomyces were related to those from cyanobacteria. Whether the cyanobacteria-like nifH amplicons obtained from soil DNA were associated with …
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N₂ fixation by subsurface populations of Trichodesmium : an important source of new nitrogen to the North Atlantic Ocean
Trichodesmium, a genus of diazotrophic cyanobacteria, is an important contributor to the marine nitrogen (N) and carbon (C) cycles. The extent to which Trichodesmium dinitrogen (N2) fixation contributes to the marine N cycle has been modeled based on abundance data and rate estimates from surface …
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Studies on the structure and function of various nif and nif- associated gene products encoded within the Azotobacter vinelandii nif gene cluster
… within the MoFe protein subunits. Based on the diazotrophic growth characteristics and substrate reduction capabilities of these mutant strains, a model is presented in which potential metallocluster binding sites within the MoFe protein subunits are defined. In addition to analysis of the MoFe …
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Drivers And Dynamics Of Harmful Algal Blooms: Understanding Nitrogen Fixation And Bloom Composition In Minnesota Temperate Lakes
… persistence, and potentially toxicity. Likewise, diazotrophic microbes (capable of fixing nitrogen) may play a role in transitions in microbial community composition, particularly under nitrogen-limited conditions. Despite its potential importance, nitrogen fixation remains understudied and …
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In the Margins: Reconsidering the Range and Contribution of Diazotrophs in Nearshore Environments
… suggests that the niche preferences of distinct diazotrophic (N<sub>2</sub> fixing) clades differ due to their metabolic and ecological diversity, hampering efforts to close the N budget and model N<sub>2</sub> fixation accurately. Here, I explore the range of N<sub>2</sub> fixation across …
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Characterization of a major cluster of genes involved in nitrogen fixation and another required for indole-3-acetic acid biosynthesis in the sugarcane endophyte, Acetobacter diazotrophicus
Acetobacter diazotrophicus is a true endophyte of sugarcane and is often found in plants grown in agricultural areas of low nitrogen fertilizer input. Results from our laboratory, using mutant strains of A. diazotrophicus unable to fix nitrogen, have shown that there are two beneficial effects of …
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N2 fixation by subsurface populations of Trichodesmium : an important source of new nitrogen to the North Atlantic Ocean
Trichodesmium, a genus of diazotrophic cyanobacteria, is an important contributor to the marine nitrogen (N) and carbon (C) cycles. The extent to which Trichodesmium dinitrogen (N2) fixation contributes to the marine N cycle has been modeled based on abundance data and rate estimates from surface …
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The Synthetic Biology of N2-Fixing Cyanobacteria for Photosynthetic Terpenoid Production
… glycogendeficiency in the cyanobacterium during diazotrophic growth. In chapter 6, we focus on introducing a synthetic photorespiratory bypass to reduce photorespiration and increase carbon partitioning towards linalool synthesis.</p>
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Use of 15N2 for direct measurement of free-living N2 fixation
… and incubation period. Among the major findings, diazotrophic activity was greatest with surface (0−7.5 cm) sampling, and storage effects were minimized when field-moist samples were kept for ≤ 1 d at room temperature (25°C) or in a refrigerator (5°C) with or without sieving (< 2 mm). In the …
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Characterization of Two Genes Up-regulated During Heterocyst Development in the Cyanobacterium Anabaena sp. strain PCC 7120.
… and Anabaena variabilis, two filamentous, diazotrophic cyanobacteria. Additionally, alr4311 appears to be most similar to ABC transporters involved in the import of cobalt, while all4312 was most similar to uncharacterized response regulators. The transcripts of alr4311 and all4312 are …
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