Sökning: "Fixation of nitrogen"

Visar resultat 21 - 25 av 79 avhandlingar innehållade orden Fixation of nitrogen.

  1. 21. Significance of N2 fixing planktonic symbioses for open ocean ecosystems

    Författare :Marcus Stenegren; Rachel A. Foster; Agneta Andersson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nitrogen fixation; diazotrophs; symbiosis; DDA; cyanobacteria; qPCR; piecewise SEM; microarray; tropics; subtropics; marine; open ocean; Richelia; Calothrix; Marine Ecology; marin ekologi;

    Sammanfattning : Di-nitrogen (N2) fixers, also called diazotrophs, are able to reduce atmospheric N2 into bioavailable nitrogen, giving them an advantage in open ocean regions with low dissolved inorganic nitrogen concentrations. The focus of this thesis are three lineages of symbiotic heterocystous filamentous types (het-1, het-2 and het-3), that associate with several genera of microalgae called diatoms (collectively referred to as Diatom Diazotroph Associations, DDAs). LÄS MER

  3. 22. Nitrogen fixation by cyanobacteria in Indian soils and regulation of cyanobacterial morphogenesis

    Författare :Pawan Sharma; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  4. 23. On the ecophysiology of Baltic cyanobacteria focusing on bottom-up factors

    Författare :Malin Mohlin; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Allelopathy; Aphanizomenon sp.; Baltic Sea; Cyanobacteria; Diazotrophic; Multi-factorial; Nitrogen; Nodularin; photosynthetic active radiation; Phosphorus; ultraviolet radiation; UV-A; UV-B;

    Sammanfattning : Cyanobacterial blooms in the Baltic Sea are dominated by diazotrophic cyanobacteria, i.e. Aphanizomenon sp. and Nodularia spumigena. LÄS MER

  5. 24. Regulation of ammonium assimilation and nitrogen fixation in photosynthetic bacteria : studies on the glnB gene and the P II protein in Rhodospirillum rubrum

    Författare :Magnus Johansson; Christina Kennedy; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; biokemi; Biochemistry;

    Sammanfattning : .... LÄS MER

  7. 25. Towards an understanding of diazocyte development and diazotrophy in the marine cyanobacterium Trichodesmium

    Författare :Gustaf Sandh; Birgitta Bergman; Rehab El-Shehawy; Louis Sherman; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cyanobacteria; Trichodesmium; diazocyte; cell differentiation; nitrogen fixation; cell division; flavodoxin; Plant physiology; Växtfysiologi; Plant Physiology; växtfysiologi;

    Sammanfattning : Trichodesmium is a filamentous cyanobacterium of great ecological significance as it contributes significantly to primary production in oceans through an efficient nitrogen fixation strategy, including a unique cell type, the diazocyte. The aim of this thesis was to generate a deeper understanding of the structural and molecular background related to the development of diazocytes and the maintenance of diazotrophy in Trichodesmium erythraeum IMS101. LÄS MER