Comparison of the Nitrogen-15 Uptake and Acetylene Reduction Methods for Estimating the Rates of Nitrogen Fixation by Freshwater Blue-Green Algae

1980 ◽  
Vol 37 (3) ◽  
pp. 488-493 ◽  
Author(s):  
B. M. Graham ◽  
R. D. Hamilton ◽  
N. E. R. Campbell
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Experimental Lakes Area ◽  
Method Of Calculation ◽  
Blue Green Algae ◽  
Northwestern Ontario ◽  
Green Algal ◽  
Reduction Methods ◽  
Ratio Determination ◽  
Relationship Of

The relationship of acetylene reduction to nitrogen-15 uptake was investigated using blue-green algal populations in three lakes in the Experimental Lakes Area, northwestern Ontario. Nitrogen fixation rates, as estimated with both techniques, were compared and acetylene to nitrogen ratios determined. Lake ratios ranged from 6.3 to 9.1 moles of acetylene reduced per mole of nitrogen fixed varying from sample to sample and also with the method of calculation. Explanations of the discrepancies between theoretical and empirical ratios are discussed; these include hypotheses of excretion of assimilated nitrogen-15 labeled material and interference from nitrogenase-mediated hydrogen production.Key words: acetylene reduction, nitrogen-15 uptake, nitrogen fixation, C2H2/N2 ratio determination

Aquatic acetylene-reduction techniques: solutions to several problems

1976 ◽  
Vol 22 (1) ◽  
pp. 43-51 ◽  
Author(s):  
R. J. Flett ◽  
R. D. Hamilton ◽  
N. E. R. Campbell
Keyword(s):  
Nitrogen Fixation ◽  
Depth Profile ◽  
Acetylene Reduction ◽  
Canadian Shield ◽  
Experimental Lakes Area ◽  
Reduction Techniques ◽  
Northwestern Ontario ◽  
Refined Technique

Previous methods of performing aquatic acetylene-reduction assays are described and several problems associated with them are discussed. A refinement of these older techniques is introduced and problems that it overcomes are also discussed. A depth profile of nitrogen fixation (C2H4 production), obtained by the refined technique, is shown for a fertilized Canadian Shield lake in the Experimental Lakes Area of northwestern Ontario.

scholarly journals Nitrogen Fixation in Canadian Precambrian Shield Lakes

1980 ◽  
Vol 37 (3) ◽  
pp. 494-505 ◽  
Author(s):  
Robert J. Flett ◽  
David W. Schindler ◽  
Robert D. Hamilton ◽  
Norman E. R. Campbell
Keyword(s):  
Nitrogen Fixation ◽  
Green Algae ◽  
Acetylene Reduction ◽  
Low Oxygen ◽  
Experimental Lakes Area ◽  
Blue Green Algae ◽  
Methane Oxidizing Bacteria ◽  
Bloom Formation ◽  
Littoral Sediments ◽  
Shield Lakes

Acetylene reduction assays in the water columns of several artificially eutrophied lakes in the Experimental Lakes Area revealed that nitrogen fixation by planktonic blue-green algae could supply a significant portion of the nitrogen income to these lakes. In situ 15N2 uptake experiments in one lake indicated that nitrogen fixation was proceeding at a slow rate in the low oxygen region of the thermocline, probably via methane oxidizing bacteria. Other 15N2 uptake experiments in the littoral sediments of an oligotrophic lake failed to detect nitrogen fixation. Generally, algal nitrogen fixation occurred in Shield lakes that were subject to total N:total P loading ratios (wt/wt) of less than approximately 10. This suggests that in these lakes phosphorus removal from loading is the best technique for eutrophication abatement and that nitrogen removal, when applied by itself, may be detrimental because it could encourage bloom formation of nitrogen fixing blue-green algae.Key words: nitrogen fixation, eutrophication, blue-green algae, acetylene reduction, nitrogen-15

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.

scholarly journals Optimization of the 15N2 incorporation and acetylene reduction methods for free-living nitrogen fixation

2019 ◽  
Vol 445 (1-2) ◽  
pp. 595-611 ◽  
Author(s):  
Darian N. Smercina ◽  
Sarah E. Evans ◽  
Maren L. Friesen ◽  
Lisa K. Tiemann
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Free Living ◽  
Reduction Methods ◽  
15N2 Incorporation

Comparison of 15N2 and acetylene reduction methods for the measurement of nitrogen fixation by Baltic Sea cyanobacteria

Phycologia ◽  
1996 ◽  
Vol 35 (sup6) ◽  
pp. 140-146 ◽  
Author(s):  
P. Moisander ◽  
J. Lehtimäki ◽  
K. Sivonen ◽  
K. Kononen
Keyword(s):  
Nitrogen Fixation ◽  
Baltic Sea ◽  
Acetylene Reduction ◽  
Reduction Methods
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