scholarly journals Biological nitrogen fixation (acetylene reduction) associated with blue-green algal (cyanobacterial) communities in the Beachwood Mangrove Nature Reserve. I. The effect of environmental factors on acetylene reduction activity

1989 ◽  
Vol 55 (4) ◽  
pp. 438-446 ◽  
Author(s):  
Fiona D. Mann ◽  
T.D. Steinke
1979 ◽  
Vol 25 (10) ◽  
pp. 1197-1200 ◽  
Author(s):  
R. C. Shearman ◽  
W. L. Pedersen ◽  
R. V. Klucas ◽  
E. J. Kinbacher

Associative nitrogen fixation in Kentucky bluegrass (Poa pratensis L.) turfs inoculated with five nitrogen-fixing bacterial isolates was evaluated using the acetylene reduction assay and nitrogen accumulation as indicators of fixation. 'Park' and 'Nugget' Kentucky bluegrass turfs were grown in controlled environment chambers and inoculated with Klebsiella pneumoniae (W-2, W-6, and W-14), Erwinia herbicola (W-8), and Enterobacter cloacae (W-11). 'Park' inoculated with K. pneumoniae (W-6) had significant acetylene reduction activity using undisturbed turfs. Other treatments including turfs treated with heat-killed cells had no significant difference in acetylene reduction. In a second study, 'Park' and 'South Dakota Certified' turfs were grown in a greenhouse and inoculated with K. pneumoniae (W-6) and E. herbicola (W-8). 'Park' inoculated with K. pneumoniae (W-6) had increased acetylene reduction activity rates and also a greater nitrogen accumulation in aerial tissues when compared to controls. Acetylene reduction activity was correlated (r = 0.92) to nitrogen accumulation. Other treatments did not effectively increase acetylene reduction activity or nitrogen accumulation.


1988 ◽  
Vol 39 (3) ◽  
pp. 409 ◽  
Author(s):  
GN Mundy ◽  
HR Jones ◽  
WK Mason

The effect of flood irrigation on clover nitrogen fixation (acetylene reduction activity) was investigated in unfertilized pastures and pastures fertilized with 100 kg N/ha as NH4N03. During the experiment acetylene reduction activities were monitored between successive flood irrigations. The rate of ethylene production increased with decreasing soil water content, peaking 13 days after irrigation. Measured nodule activity then declined, possibly owing to water stress. Nitrogen fertilizer reduced acetylene reduction activities to about half that of the unfertilized pastures. For most of the irrigation cycle acetylene reduction by the pasture was below the measured maximum.


1985 ◽  
Vol 63 (5) ◽  
pp. 974-979 ◽  
Author(s):  
Jim D. Karagatzides ◽  
Martin C. Lewis ◽  
Herbert M. Schulman

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.


1985 ◽  
Vol 31 (4) ◽  
pp. 327-330 ◽  
Author(s):  
Tran Phuoc Duong ◽  
James M. Tiedje

Nitrogen fixation as measured by acetylene conversion to ethylene was found to be common for duckweed blooms on ponds, lakes, and streams in Michigan. Twenty-six of 29 sites with duckweed sampled over a 2-year period showed acetylene reduction activity (ARA). These activities corresponded to N inputs of 3.7–7.5 kg N∙ha−1 per annual cycle for typical blooms but dense Lemna trisulca blooms could be 10 times greater. The ARA was stimulated five- to six-fold by light, was not removed when plants were shaken in water, and was usually associated with the leaves and not the roots. Colonies of heterocyst-bearing cyanobacteria of the genera Nostoc, Gloeotrichia, Anabaena, Calothrix, and Cylindrospermum were observed attached to the lower epidermis or in the reproductive pockets of leaves of Spirodela and Lemna plants but not on Wolffia plants. The ARA correlated reasonably well with the density of cyanobacterial colonies observed. The duckweed appeared to provide a more favorable environment for the cyanobacteria which should result in enhanced nitrogen inputs to aquatic and sediment environments harboring duckweed. The N2 fixation was not sufficient, however, to meet all the nitrogen needs of the duckweed bloom.


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