Can nitrogen gas be deficient for nitrogen fixation in lakes?

2007 ◽  
Vol 202 (3-4) ◽  
pp. 362-372 ◽  
Author(s):  
Andreas C. Bryhn ◽  
Thorsten Blenckner
Keyword(s):  
Nitrogen Fixation ◽  
Nitrogen Gas

Nitrogen fixation by cell-free extracts of Klebsiella pneumoniae

1968 ◽  
Vol 14 (1) ◽  
pp. 33-38 ◽  
Author(s):  
M. C. Mahl ◽  
P. W. Wilson
Keyword(s):  
Nitrogen Fixation ◽  
Klebsiella Pneumoniae ◽  
Azotobacter Vinelandii ◽  
Ammonium Ion ◽  
Michaelis Constant ◽  
Nitrogen Gas ◽  
Aerobacter Aerogenes ◽  
Free System ◽  
Evolving System ◽  
A Cell

A cell-free system which permits nitrogen fixation by extracts of Klebsiella pneumoniae M5al (formerly Aerobacter aerogenes) has been developed. It is, essentially, that system described by Bulen and associates for Azotobacter vinelandii, utilizing ATP as a source of energy and dithionite as a source of electrons. The Michaelis constant for fixation has been estimated to be 0.12 atm. The extracts possessed an ATP-dependent hydrogen evolving system. Hydrogen evolution from these extracts was less under nitrogen than under helium in the presence of ATP. Nitrogen gas appears to be the inducer of nitrogen fixation. In the absence of N2, no induction of nitrogenase occurs. Nitrogenase is absent in cells grown on NH4+-N. There is a lag of about 13 h after the introduction of N2 gas into a culture which has depleted its supply of NH4+-N before nitrogenase can be detected. For reasons discussed in the text, this conclusion must be regarded as tentative at this time. Ammonium ion appears to prevent the synthesis of new molecules of nitrogenase without affecting the activity of those already formed.

Real-time imaging of nitrogen fixation in an intact soybean plant with nodules using13N-labeled nitrogen gas

2009 ◽  
Vol 55 (5) ◽  
pp. 660-666 ◽  
Author(s):  
Satomi Ishii ◽  
Nobuo Suzui ◽  
Sayuri Ito ◽  
Noriko S. Ishioka ◽  
Naoki Kawachi ◽  
...  
Keyword(s):  
Nitrogen Fixation ◽  
Real Time ◽  
Soybean Plant ◽  
Nitrogen Gas ◽  
Real Time Imaging

The nitrogen cycle

2018 ◽  
Author(s):  
David L. Kirchman
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Fixation ◽  
Nitrogen Cycle ◽  
Ammonia Oxidation ◽  
Heterotrophic Bacteria ◽  
Ammonium Nitrogen ◽  
Gas Production ◽  
Ammonia Oxidizing Bacteria ◽  
Nitrogen Gas ◽  
Chemolithoautotrophic Bacteria

Nitrogen is required for the biosynthesis of many cellular components and can take on many oxidation states, ranging from −3 to +5. Consequently, nitrogen compounds can act as either electron donors (chemolithotrophy) or electron acceptors (anaerobic respiration). The nitrogen cycle starts with nitrogen fixation, the reduction of nitrogen gas to ammonium. Nitrogen fixation is carried out only by prokaryotes, mainly some cyanobacteria and heterotrophic bacteria. The ammonium resulting from nitrogen fixation is quickly used by many organisms for biosynthesis, being preferred over nitrate as a nitrogen source. It is also oxidized aerobically by chemolithoautotrophic bacteria and archaea during the first step of nitrification. The second step, nitrite oxidation, is carried out by other bacteria not involved in ammonia oxidation, resulting in the formation of nitrate. Some bacteria are capable of carrying out both steps (“comammox”). This nitrate can then be reduced to nitrogen gas or nitrous oxide during denitrification. It can be reduced to ammonium, a process called “dissimilatory nitrate reduction to ammonium.” Nitrogen gas is also released by anaerobic oxidation of ammonium (“anammox”) which is carried out by bacteria in the Planctomycetes phylum. The theoretical contribution of anammox to total nitrogen gas release is 29%, but the actual contribution varies greatly. Another gas in the nitrogen cycle, nitrous oxide, is a greenhouse gas produced by ammonia-oxidizing bacteria and archaea. The available data indicate that the global nitrogen cycle is in balance, with losses from nitrogen gas production equaling gains via nitrogen fixation. But excess nitrogen from fertilizers is contributing to local imbalances and several environmental problems in drinking waters, reservoirs, lakes, and coastal oceans.

scholarly journals Effect of Nitrogen Gas, Irradiated with a Beta-Ray Source, on Nitrogen Fixation in Continuous Cultures of Azotobacter vinelandii.

1963 ◽  
Vol 17 ◽  
pp. 2225-2229 ◽  
Author(s):  
Bengt Zacharias ◽  
Raimo Raunio ◽  
Kirsti Lampiaho ◽  
Carl Djerassi ◽  
Jon Munch-Petersen
Keyword(s):  
Nitrogen Fixation ◽  
Azotobacter Vinelandii ◽  
Nitrogen Gas ◽  
Continuous Cultures

Nitrogen Fixation, Agriculture, and the Environment

2004 ◽  
Author(s):  
G. J. Leigh
Keyword(s):  
Nitrogen Fixation ◽  
Soil Fertility ◽  
Food Systems ◽  
Agricultural Productivity ◽  
Human Beings ◽  
Nitrogen Gas ◽  
The World ◽  
Essential Nutrient ◽  
Sufficient Food ◽  
The Way

This book tells the story of how humans have used their ingenuity throughout history to maintain soil fertility and to avoid famine through productive agriculture. The struggle to provide sufficient food has been a preoccupation of humanity since the earliest times. As circumstances have changed and as lifestyles have changed, the way in which the food supply has been ensured has also changed. The story of how different peoples have developed solutions to what is essentially the same problem tells us much about human beings of all kinds and in all ages. It shows us how humans have optimised the opportunities available to them by using the resources, both physical and intellectual, that have been available to them. It shows us the similarity amongst human beings of every era. It also demonstrates how one generation builds upon the knowledge of its predecessors to provide a solution that is appropriate to the new conditions, and it also illustrates the way in which science is gradually and painfully built by generations of researchers in a cooperative undertaking that slowly refines the models of reality used to analyse nature. Traditionally, agriculturalists have tended to be conservative, and this is very understandable. It is stupid to experiment with questionable new methods if you know that the old techniques work and that not using them will risk a year of famine. The Egyptian and the Britons depicted ploughing with very similar implements in figure 1.1 would probably have shared many ideas on how best to raise crops. A survey of how some ancient civilisations attempted to solve the problems of maintaining soil fertility is given in chapter 2. Many of their techniques are still applied somewhere in the world to this day. The main focus of this book will be on the story of the essential nutrient nitrogen because nitrogen is often the element whose supply limits the agricultural productivity of many food systems. Nitrogen is an element that many people know a little about. Nitrogen gas comprises about 80% of Earth’s atmosphere, though this was not known 250 years ago, nor would such a statement have made much sense then.

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