Nitrogen fixation in relation to Hudsonia tomentosa: a pioneer species in sand dunes, northeastern Alberta

1986 ◽  
Vol 64 (11) ◽  
pp. 2495-2501
Author(s):  
S. D. Nelson ◽  
L. C. Buss ◽  
J. M. Mayo
Keyword(s):  
Green Algae ◽  
Pinus Banksiana ◽  
Sand Dunes ◽  
Vascular Plant ◽  
Green Sand ◽  
Fixed Nitrogen ◽  
Free Living ◽  
Blue Green Algae ◽  
Study Sites ◽  
Northeastern Alberta

Blue-green algae, including species of Oscillatoria, Lyngbya, Microcystis, and Nostocaceae were isolated from green sand associated with Hudsonia tomentosa. Green sands were consistently found in the buried phyllosphere and rhizosphere of Hudsonia and on the surface to varying depths under Hudsonia plants. Organisms in these sands fixed nitrogen at maximum rates of 1 nmol C2H4∙g soil−1∙h−1. Seasonal variation in rates was largely explained by optima of 30% soil water content and 28 to 33 °C soil temperature. Green sands were not associated with any other vascular plant at the study sites. The results suggest a preference of free-living blue-green algae for Hudsonia which may relate to the ability of this dwarf shrub to colonize nutrient-poor sand sites, such as blowouts and sand dunes in the Pinus banksiana – lichen woodlands of northeastern Alberta.

scholarly journals Studies on Nitrogen Fixation by Blue-Green Algae

1942 ◽  
Vol 19 (1) ◽  
pp. 78-87
Author(s):  
G. E. FOGG
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Anabaena Cylindrica ◽  
Fixed Nitrogen ◽  
Blue Green Algae ◽  
Combined Nitrogen

1. Anabaena cylindrica Lemin. has been obtained in pure unialgal bacteria-free culture. 2. Due precautions having been taken against contamination by other organisms and error due to absorption of fixed nitrogen from the atmosphere, this alga has been shown to possess the capacity of fixing nitrogen. 3. Nitrogen fixation does not take place in the presence of a sufficient quantity of readily available combined nitrogen.

scholarly journals Nitrogen Fixation in the Coralloid Roots of Macrozamia Communis L. Johnson

1965 ◽  
Vol 18 (6) ◽  
pp. 1135 ◽  
Author(s):  
FJ Bergersen ◽  
GS Kennedy ◽  
W Wittmann
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Intact Plant ◽  
Large Excess ◽  
Fixed Nitrogen ◽  
Blue Green Algae ◽  
Plant Parts ◽  
Isotopic Method ◽  
Coralloid Roots

Coralloid roots of Macrozamia communis have been shown by the isotopic method to fix nitrogen when they contain the endophytic blue�green algae. Immature coralloid roots devoid of the endophyte did not fix nitrogen. Coralloid roots from glasshouse-grown plants fixed 2� 7 times as much nitrogen when illuminated than they did in the dark and the IfiN excess was about equally divided between fractions soluble or insoluble in 3N HCI. Coralloid roots excavated from beneath large fieldgrown plants were opaque and did not fix more nitrogen when illuminated than they did in the dark. Most of the newly fixed nitrogen was found in the buffered sucrose extract of crushed tissue. When an intact plant bearing coralloid roots was exposed to an atmosphere containing a large excess of IfiN. for 48 hr the IfiN was found to be distributed through the plant parts. Nitrogen fixed in the coralloid roots is thus available for the growth of the plant. The coralloid roots evolved small amounts of hydrogen.

Nitrogen fixation in the high arctic tundra at Sarcpa Lake, Northwest Territories

1985 ◽  
Vol 63 (5) ◽  
pp. 974-979 ◽  
Author(s):  
Jim D. Karagatzides ◽  
Martin C. Lewis ◽  
Herbert M. Schulman
Keyword(s):  
Nitrogen Fixation ◽  
Northwest Territories ◽  
Acetylene Reduction ◽  
Biological Nitrogen Fixation ◽  
Arctic Tundra ◽  
High Arctic ◽  
Fixed Nitrogen ◽  
Free Living ◽  
Blue Green Algae ◽  
Biological Nitrogen

The acetylene reduction assay was used to examine biological nitrogen fixation in the high arctic tundra at Sarcpa Lake, Northwest Territories (68°32′ N, 83°19′ W). The highest rates of acetylene reduction (9.37 ± 3.19 μmol C2H4 m−2 h−1) were in habitats that had a high density of the legumes Oxytropis maydelliana, O. arctobia, and Astragalus alpinus. Nitrogen fixation in the wet soils along the shore of a small lake was similar (8.87 ± 4.35 μmol C2H4 m−2 h−1) because of the blue-green alga Nostoc, which associates with mosses. Free-living blue-green algae and lichens made insignificant contributions to the total nitrogen fixation budget because they were uncommon and fixed nitrogen at a slower rate. Nitrogen-fixing lichens in the area included Stereocaulon arenarium and S. rivulorum. It is concluded that legumes have a significant input to the biological nitrogen fixation budget at Sarcpa Lake.

Nitrogen Fixation by Blue-green Algae of the Lizard Island Area of the Great Barrier Reef

1976 ◽  
Vol 3 (1) ◽  
pp. 41 ◽  
Author(s):  
RH Burris
Keyword(s):  
Great Barrier Reef ◽  
Green Algae ◽  
Rock Surface ◽  
Barrier Reef ◽  
Fixed Nitrogen ◽  
Blue Green Algae ◽  
Average Ratio ◽  
Island Area ◽  
Partial Pressures ◽  
Lizard Island

Reduction of acetylene and 15N2 by blue-green algae and other organisms from the Lizard Island area of the Great Barrier Reef was measured. The effects of storage of the algae, the partial pressures of acetylene and oxygen, and light intensity were studied. The average ratio of acetylene to N2 reduced was 1.9. With this factor, it was calculated that 6.8 - 30.6 kg nitrogen was fixed annually per hectare of rock surface in the intertidal zone. Fixation of nitrogen by blue-green algae can contribute a substantial portion of the fixed nitrogen required for maintaining the flora and fauna of the coral reef community.

Special aspects of nitrogen fixation by blue-green algae

1969 ◽  
Vol 172 (1029) ◽  
pp. 357-366 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Nitrogen Fixation ◽  
Light Intensity ◽  
Green Algae ◽  
Limited Extent ◽  
Anabaena Cylindrica ◽  
Fixed Nitrogen ◽  
Normal Cells ◽  
Blue Green Algae ◽  
Reducing Potential

When carbon dioxide fixation was over 90 % inhibited by CMU , nitrogen fixation remained unaffected in nitrogen-starved cells of Anabaena cylindrica . In normal cells under the same conditions nitrogen fixation was about 50 % inhibited by CMU . These data suggest, first, that nitrogen fixation in this organism is independent of reducing potential generated by non-cyclic photo-electron transport and, secondly, that nitrogen fixation is stimulated by photosynthetically produced carbon skeletons to assimilate the fixed nitrogen. Although nitrogen fixation occurred to a limited extent in the dark, increasing light intensity stimulated nitrogen fixation both in the presence and absence of CMU . This suggests that light-generated ATP is required for nitrogen fixation in this alga. A ratio of pyruvate decarboxylation to nitrogen fixation of 3:1 has been established for A. cylindrica . This accords with the hypothesis that pyruvate acts as a hydrogen donor for nitrogen reduction and that provision of the required reductant is independent of photosynthesis in blue-green algae.

Novel aspects of nitrogen fixation

1977 ◽  
Vol 9 (4) ◽  
pp. 180-185 ◽  
Author(s):  
J M Day ◽  
J F Witty
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Root Nodule ◽  
Atmospheric Nitrogen ◽  
Biological Fixation ◽  
Free Living ◽  
Tropical Grasses ◽  
Blue Green Algae ◽  
Synthetic Fertilizers ◽  
Living Bacteria

Only a fraction of the total agricultural need for nitrogen comes from natural or synthetic fertilizers. The remainder is satisfied largely through the biological fixation of atmospheric nitrogen. Whilst this is most efficiently effected by the Rhizobium-legume root nodule, free-living bacteria and blue-green algae are known to be capable of fixing appreciable amounts. Recently, attention has been focused on bacteria closely associated with roots of certain tropical grasses.

Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

1967 ◽  
Vol 25 ◽  
pp. 74-75
Author(s):  
L. V. Leak
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Green Algae ◽  
Three Dimensional ◽  
Freeze Fracture ◽  
Electron Microscopic ◽  
Photosynthetic Membranes ◽  
Blue Green Algae ◽  
Cell Biol ◽  
Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

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