Sökning: "nitrogenase activity"

Visar resultat 1 - 5 av 14 avhandlingar innehållade orden nitrogenase activity.

  1. 1. Genetic variability and nitrogenase activity of cyanobacterial communities associated with tropical seagrass meadows (western Indian Ocean)

    Författare :Mariam Hamisi; Birgitta Bergman; Thomas Lyimo; Beatriz Díez; Lucas Stal; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cyanobacteria; nitrogenase activity; diazotrophs; seagrass; western Indian ocean; Plant physiology; Växtfysiologi; Plant Physiology; växtfysiologi;

    Sammanfattning : Tropical seagrass ecosystems are highly productive and important for sustaining marine life and associated coastal societies. In this study, the diversity and role of nitrogen-fixing cyanobacteria associated with five common seagrass genera in coastal regions of the western Indian Ocean (WIO; Tanzania) were examined, as well as the impact of anthropogenic activities. LÄS MER

  3. 2. Distribution and activity of nitrogen-fixing bacteria in marine and estuarine waters

    Författare :Hanna Farnelid; Lasse Riemann; Jonathan Zehr; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 454-pyrosequencing; diazotrophs; heterotrophic bacteria; marine bacteria; marine microbial ecology; microbiology; nifH; nitrogenase; nitrogen fixation; PCR; qPCR; Mikrobiologi; Microbiology;

    Sammanfattning : In aquatic environments the availability of nitrogen (N) generally limits primary production. N2-fixing prokaryotes (diazotrophs) can convert N2 gas into ammonium and provide significant input of N into the oceans. Cyanobacteria are thought to be the main N2-fixers but diazotrophs also include a wide range of heterotrophic bacteria. LÄS MER

  4. 3. Non-cyanobacterial nitrogen fixation insights in humic freshwater lakes and ponds

    Författare :Leyden Fernandez-Vidal; Stefan Bertilsson; Sari Peura; David Walsh; Uppsala universitet; []
    Nyckelord :humic lakes; thaw ponds; non-cyanobacterial diazotrophs; nitrogen fixation; nitrogenase;

    Sammanfattning : The biological basis of nitrogen fixation beyond the canonical role of Cyanobacteria is not well understood in freshwater ecosystems. To address this gap in knowledge, the main objective of this thesis is to study non-cyanobacterial nitrogen fixation in freshwater lakes and ponds. LÄS MER

  5. 4. Functional genomics of the Baltic Sea cyanobacterium Nodularia spumigena in relation to nitrogen fixation, heterocyst differentiation and toxin production

    Författare :Simina Vintila; Rehab El-Shehawy; Peter Lindblad; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; cyanobacteria; Nodularia; nitrogen fixation; heterocyst; nitrogenase; ammonium; phosphate; nodularin; Baltic Sea; Plant physiology; Växtfysiologi; Plant Physiology; växtfysiologi;

    Sammanfattning : Nodularia spumigena is a filamentous, heterocystous cyanobacterium that dominates the annual, toxic cyanobacterial blooms in the Baltic Sea. The blooms are believed to have increased in recent years, due to eutrophication by phosphate and/or nitrogen. Toxicity of these blooms is well-documented and attributed to the hepatotoxin nodularin. LÄS MER

  7. 5. Metabolic regulation of nitrogenase in Rhodospirillum rubrum : studies on DRAG and DRAT, the regulatory proteins of dinitrogenase reductase

    Författare :Agneta Norén; Gary Robert; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biochemistry; Biokemi; Biochemistry; biokemi;

    Sammanfattning : Nitrogen fixation is catalyzed by nitrogenase, in an ATP-dependent reaction where dinitrogen is reduced to ammonium. Nitrogenase is a protein complex consisting of two proteins; dinitrogenase and dinitrogenase reductase and the reaction is only carried out by prokaryotes. LÄS MER