Conversion factor between acetylene reduction and nitrogen fixation in free-living cyanobacteria from high arctic habitats

1999 ◽  
Vol 45 (3) ◽  
pp. 223-229 ◽  
Author(s):  
Turid Liengen
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Conversion Factor ◽  
Soil Surface ◽  
High Arctic ◽  
Acetylene Reduction Activity ◽  
Nostoc Commune ◽  
Free Living ◽  
Conversion Factors ◽  
N Incorporation

The conversion factor between acetylene reduction and15N incorporation in free-living cyanobacteria was determined in different high arctic habitats in the area of Ny-Ålesund (78.5°N, 11.6°E), Spitsbergen, in the summer of 1994. The experiments were carried out under constant conditions, 19°C and 200 µE·m-2·s-1. The nitrogen-fixation activities, measured as15N-incorporation, were in the range 4.01-6.54 mg N2fixed·gdw-1·day-1(dw, dry weight) in sheets of Nostoc commune and 778-1206 mg N2fixed·m-2·day-1in the cyanobacterial crusts. The acetylene reduction activities were in the range 0.72-1.91 mg ethylene produced·gdw-1·day-1of N. commune and 12.8-63.7 mg ethylene produced·m-2·day-1in the cyanobacterial crusts. The conversion factor of N. commune ranged from 0.11 to 0.48 for ethylene produced to nitrogen fixed, whereas the cyanobacterial crusts covering the soil surface gave conversion factors in the range 0.022-0.073 for ethylene produced to nitrogen fixed. An Anabaena sp., isolated from one of the habitats investigated, gave conversion factors near the theoretical factor of 4, when determined at 14.0 and 17.3°C. It was concluded that the acetylene reduction activity of free-living cyanobacteria in high arctic habitats results in underestimates of the real nitrogen-fixation activity in these environments.Key words: nitrogen fixation, acetylene reduction, conversion factor, cyanobacteria, Nostoc commune, high arctic.

Nitrogen fixation and photosynthesis in high arctic forms of Nostoc commune

1994 ◽  
Vol 72 (7) ◽  
pp. 940-945 ◽  
Author(s):  
R. Lennihan ◽  
D. M. Chapin ◽  
L. G. Dickson
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Terrestrial Ecosystems ◽  
Growing Season ◽  
High Arctic ◽  
Colony Morphology ◽  
Nostoc Commune ◽  
Devon Island ◽  
Low Levels ◽  
Temperature Optima

Nostoc commune, a colonial cyanobacterium, has been suggested as an important contributor of nitrogen to terrestrial ecosystems in the Canadian High Arctic, yet little is known about the ecophysiology of this organism in arctic environments. This study focused on the physiological performance of macroscopic colonies of N. commune found on Devon Island, N.W.T. The objectives were to examine the influence of temperature, colony morphology, and seasonal phenology on nitrogen fixation rates and the effects of light and temperature on photosynthesis. Maximum rates of acetylene reduction in N. commune (2119 nmol C2H4∙g−1∙h−1) were higher than those previously recorded for arctic N. commune but lower than values reported for temperate poulations. Depending on the time of the growing season, the temperature optimum for acetylene reduction varied from 15 °C to greater than 20 °C. Photosynthetic temperature optima did not occur below 20–25 °C (the highest temperatures measured). Light saturation of photosynthesis was reached at low levels of irradiance (100–150 μmol∙m−2∙s−1 PPFD). Acetylene reduction rates varied strongly with colony morphology. Thin, fragile, flattened colonies had higher rates than thicker, more resilient, flattened colonies or spherical colonies. Cold post-thaw temperatures appeared to delay the recovery of maximum nitrogen fixation rates for 2–3 weeks following the onset of the growing season. Compared with two other species of cyanobacteria present on Truelove Lowland (Gloeocapsa alpina and Gleotrichia sp.), N. commune had higher rates of nitrogen fixation. Key words: Nostoc commune, cyanobacteria, High Arctic, nitrogen fixation, photosynthesis.

scholarly journals Nitrogen Fixation in Pozol, a Traditional Fermented Beverage

2020 ◽  
Vol 86 (16) ◽  
Author(s):  
Jocelin Rizo ◽  
Marco A. Rogel ◽  
Daniel Guillén ◽  
Carmen Wacher ◽  
Esperanza Martinez-Romero ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Growth Promotion ◽  
Point Of View ◽  
Intestinal Microbiome ◽  
Acetylene Reduction Activity ◽  
Nitrogen Fixing ◽  
Nitrogen Fixing Bacteria ◽  
Free Living ◽  
Functional Perspective

ABSTRACT Traditional fermentations have been widely studied from the microbiological point of view, but little is known from the functional perspective. In this work, nitrogen fixation by free-living nitrogen-fixing bacteria was conclusively demonstrated in pozol, a traditional Mayan beverage prepared with nixtamalized and fermented maize dough. Three aspects of nitrogen fixation were investigated to ensure that fixation actually happens in the dough: (i) the detection of acetylene reduction activity directly in the substrate, (ii) the presence of potential diazotrophs, and (iii) an in situ increase in acetylene reduction by inoculation with one of the microorganisms isolated from the dough. Three genera were identified by sequencing the 16S rRNA and nifH genes as Kosakonia, Klebsiella, and Enterobacter, and their ability to fix nitrogen was confirmed. IMPORTANCE Nitrogen-fixing bacteria are found in different niches, as symbionts in plants, in the intestinal microbiome of several insects, and as free-living microorganisms. Their use in agriculture for plant growth promotion via biological nitrogen fixation has been extensively reported. This work demonstrates the ecological and functional importance that these bacteria can have in food fermentations, reevaluating the presence of these genera as an element that enriches the nutritional value of the dough.

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.

Environmental factors influencing the nitrogen fixation activity of free-living terrestrial cyanobacteria from a high arctic area, Spitsbergen

1999 ◽  
Vol 45 (7) ◽  
pp. 573-581 ◽  
Author(s):  
Turid Liengen
Keyword(s):  
Nitrogen Fixation ◽  
High Arctic ◽  
Nostoc Commune ◽  
Free Living ◽  
Terrestrial Cyanobacteria ◽  
Nitrogen Fixation Activity ◽  
Fixation Activity ◽  
Field Samples ◽  
Anabaena Sp ◽  
Arctic Area

The influence of environmental factors on the nitrogen fixation activity of free-living, terrestrial cyanobacteria from a high arctic area were investigated using experimental manipulations with two different types of field samples, including macroscopic sheets of Nostoc commune and soil samples with a cyanobacterial crust from a Puccinellia salt marsh. In addition, a cultured Anabaena sp. previously isolated from the salt marsh was examined. Nitrogen fixation activity was measured using the acetylene reduction method. The nitrogen fixation mainly took place in the light, but even after 12 h incubation in darkness, low activities were maintained. Phosphorus fertilization stimulated the nitrogen fixation activity, and the highest activities were obtained with about 300 μM phosphate, both in the field samples and the cultured Anabaena sp. Ammonium (28 mM) immediately inhibited the nitrogen fixation activity of the cultured Anabaena sp, whereas 14 mM urea and 540 μM glutamate led to a weaker and slower inhibition of the nitrogen fixation activity, showing that the cultured Anabaena sp. was able to assimilate these combined nitrogen sources. Nitrate did not have any inhibitory effect on nitrogen fixation activity, either in the field samples or in the cultured Anabaena sp. Both the field samples and the cultured Anabaena sp. showed tolerance against sodium chloride concentrations corresponding to the concentration in seawater. The temperature optimum of the nitrogen fixation activity of the cultured Anabaena sp. was about 20°C. Key words: nitrogen fixation, cyanobacteria, Nostoc commune, Anabaena sp., high arctic.

Environmental regulation of nitrogen fixation in a high arctic lowland ecosystem

1991 ◽  
Vol 69 (12) ◽  
pp. 2744-2755 ◽  
Author(s):  
David M. Chapin ◽  
L. C. Bliss ◽  
L. J. Bledsoe
Keyword(s):  
Nitrogen Fixation ◽  
Soil Moisture ◽  
Environmental Regulation ◽  
Acetylene Reduction ◽  
High Arctic ◽  
Spatial And Temporal Variation ◽  
Phosphorus Fertilization ◽  
Nostoc Commune ◽  
Nitrogen And Phosphorus ◽  
Devon Island

This study examined spatial and temporal variation in cyanobacterial nitrogen fixation and the environmental regulation of this variation at Truelove Lowland, Devon Island, N.W.T. Acetylene reduction rates of soil–plant cores from a variety of plant communities were measured under uniform conditions of light and temperature during the 1987 and 1988 growing seasons. Concurrent measurements of soil moisture and extractable nitrogen and phosphorus were also made. Effects of temperature, moisture, and phosphorus were examined in manipulative experiments. Acetylene reduction rates were highest in brackish environments, intermediate in mesic to hydric terrestrial and in aquatic communities, and lowest on xeric beach ridges. Rates generally increased during early season, then decreased through mid to late season. Among the three parameters examined, rates were most highly correlated to soil moisture. The temperature optimum for fixation was near 20 °C. There was a strong, but reversable, depression in acetylene reduction in response to experimental desiccation, and weekly phosphorus fertilization had a strong positive effect on fixation rates. The highest fixation rates along the marine shoreline were associated with high phosphorus input from marine algae and greater biomass of cyanobacteria. Because of the overriding importance of moisture, changes in nitrogen and phosphorus levels accompanying ecosystem development do not appear to strongly control nitrogen fixation in terrestrial, nonbrackish sites in this polar desert oasis. Key words: nitrogen fixation, environmental regulation, Devon Island, High Arctic, Nostoc commune, cyanobacteria.

Nitrogen fixation associated with 'Park' Kentucky bluegrass (Poapratensis L.)

1979 ◽  
Vol 25 (10) ◽  
pp. 1197-1200 ◽  
Author(s):  
R. C. Shearman ◽  
W. L. Pedersen ◽  
R. V. Klucas ◽  
E. J. Kinbacher
Keyword(s):  
Nitrogen Fixation ◽  
Acetylene Reduction ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Acetylene Reduction Activity ◽  
Controlled Environment ◽  
Nitrogen Accumulation ◽  
Reduction Activity ◽  
Significant Difference ◽  
Reduction Assay

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.

Nitrogen fixation and acetylene reduction in decaying conifer boles: effects of incubation time, aeration, and moisture content

1982 ◽  
Vol 12 (3) ◽  
pp. 646-652 ◽  
Author(s):  
Warwick B. Silvester ◽  
Phillip Sollins ◽  
Thomas Verhoeven ◽  
Steven P. Cline
Keyword(s):  
Nitrogen Fixation ◽  
Moisture Content ◽  
Forest Ecosystem ◽  
Acetylene Reduction ◽  
Preliminary Survey ◽  
Anaerobic Conditions ◽  
Free Living ◽  
Living Organisms ◽  
Low Activity

Free-living microaerophiles fixed 15N2 and reduced acetylene in fallen tree boles at two old-growth Pseudotsugamenziesii stands in western Oregon. Acetylene reduction was most rapid under an atmosphere of 2–10% O2, whereas under prolonged anaerobic conditions it was at or below detection limits. Acetylene reduction rates increased up to fourfold during long-term incubations in acetylene (> 12 h). Ratios of acetylene reduction to N2 fixation frequently exceeded 6.0 during such long-term incubations but averaged 3.5 when samples were incubated < 7 h; consequently, long-term incubation of low-activity material in acetylene should be avoided. A preliminary survey indicated that N2 fixation by free-living organisms in fallen boles was less than other potential N inputs to fallen boles and to the forest ecosystem.

Nitrogen fixation activity by white clover pastures during flood irrigation cycles

1988 ◽  
Vol 39 (3) ◽  
pp. 409 ◽  
Author(s):  
GN Mundy ◽  
HR Jones ◽  
WK Mason
Keyword(s):  
Nitrogen Fixation ◽  
Water Stress ◽  
White Clover ◽  
Nitrogen Fertilizer ◽  
Ethylene Production ◽  
Acetylene Reduction ◽  
Acetylene Reduction Activity ◽  
Flood Irrigation ◽  
Reduction Activity ◽  
Nitrogen Fixation Activity

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.

Nitrogen fixation by naturally occurring duckweed–cyanobacterial associations

1985 ◽  
Vol 31 (4) ◽  
pp. 327-330 ◽  
Author(s):  
Tran Phuoc Duong ◽  
James M. Tiedje
Keyword(s):  
Nitrogen Fixation ◽  
Annual Cycle ◽  
Acetylene Reduction ◽  
Acetylene Reduction Activity ◽  
Lower Epidermis ◽  
Reduction Activity ◽  
Naturally Occurring ◽  
Favorable Environment ◽  
Nitrogen Inputs

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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