Metastable polymers of the nitrogen oxides. 2. Open-chain polymers of the nitric oxide dimers and of nitrous oxide: a MNDO/AM1 study

1992 ◽  
Vol 96 (2) ◽  
pp. 594-603 ◽  
Author(s):  
Walter H. Jones
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Nitrogen Oxides ◽  
Open Chain

scholarly journals Nitrite Reductase of Nitrosomonas europaea Is Not Essential for Production of Gaseous Nitrogen Oxides and Confers Tolerance to Nitrite

2002 ◽  
Vol 184 (9) ◽  
pp. 2557-2560 ◽  
Author(s):  
Hubertus J. E. Beaumont ◽  
Norman G. Hommes ◽  
Luis A. Sayavedra-Soto ◽  
Daniel J. Arp ◽  
David M. Arciero ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Nitrogen Oxides ◽  
Nitrite Reductase ◽  
Nitrosomonas Europaea ◽  
Wild Type ◽  
Gaseous Nitrogen ◽  
Cell Extracts

ABSTRACT A gene that encodes a periplasmic copper-type nitrite reductase (NirK) was identified in Nitrosomonas europaea. Disruption of this gene resulted in the disappearance of Nir activity in cell extracts. The nitrite tolerance of NirK-deficient cells was lower than that of wild-type cells. Unexpectedly, NirK-deficient cells still produced nitric oxide (NO) and nitrous oxide (N2O), the latter in greater amounts than that of wild-type cells. This demonstrates that NirK is not essential for the production of NO and N2O by N. europaea. Inactivation of the putative fnr gene showed that Fnr is not essential for the expression of nirK.

Emissions of nitrous oxide and nitric oxide associated with the decomposition of arable crop residues on a sandy loam soil in Eastern England

Agronomie ◽  
2002 ◽  
Vol 22 (7-8) ◽  
pp. 731-738 ◽  
Author(s):  
Roland Harrison ◽  
Sharon Ellis ◽  
Roy Cross ◽  
James Harrison Hodgson
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Crop Residues ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Arable Crop ◽  
Loam Soil

The complete denitrification pathway of the symbiotic, nitrogen-fixing bacterium Bradyrhizobium japonicum

2005 ◽  
Vol 33 (1) ◽  
pp. 141-144 ◽  
Author(s):  
E.J. Bedmar ◽  
E.F. Robles ◽  
M.J. Delgado
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Bradyrhizobium Japonicum ◽  
Mutational Analysis ◽  
Control Level ◽  
Gene Clusters ◽  
Alternative Form ◽  
Nitrate Respiration ◽  
Regulatory Cascade ◽  
Denitrification Genes

Denitrification is an alternative form of respiration in which bacteria sequentially reduce nitrate or nitrite to nitrogen gas by the intermediates nitric oxide and nitrous oxide when oxygen concentrations are limiting. In Bradyrhizobium japonicum, the N2-fixing microsymbiont of soya beans, denitrification depends on the napEDABC, nirK, norCBQD, and nosRZDFYLX gene clusters encoding nitrate-, nitrite-, nitric oxide- and nitrous oxide-reductase respectively. Mutational analysis of the B. japonicum nap genes has demonstrated that the periplasmic nitrate reductase is the only enzyme responsible for nitrate respiration in this bacterium. Regulatory studies using transcriptional lacZ fusions to the nirK, norCBQD and nosRZDFYLX promoter region indicated that microaerobic induction of these promoters is dependent on the fixLJ and fixK2 genes whose products form the FixLJ–FixK2 regulatory cascade. Besides FixK2, another protein, nitrite and nitric oxide respiratory regulator, has been shown to be required for N-oxide regulation of the B. japonicum nirK and norCBQD genes. Thus nitrite and nitric oxide respiratory regulator adds to the FixLJ–FixK2 cascade an additional control level which integrates the N-oxide signal that is critical for maximal induction of the B. japonicum denitrification genes. However, the identity of the signalling molecule and the sensing mechanism remains unknown.

Reduction of Nitrogen Oxides by Injecting Nitric Oxide into a Hydrogen Engine: A Micro-kinetic Analysis

2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Suhani Agarwal ◽  
Vaibhav Srivastava ◽  
Pranav V. Kherdekar ◽  
Divesh Bhatia
Keyword(s):  
Nitric Oxide ◽  
Nitrogen Oxides ◽  
Kinetic Analysis

scholarly journals Emissions of Nitrous Oxide and Nitric Oxide from Soils of Native and Exotic Ecosystems of the Amazon and Cerrado Regions of Brazil

2001 ◽  
Vol 1 ◽  
pp. 312-319 ◽  
Author(s):  
Eric A. Davidson ◽  
Mercedes M.C. Bustamante ◽  
Alexandre de Siqueira Pinto
Keyword(s):  
Nitric Oxide ◽  
Land Use ◽  
Nitrous Oxide ◽  
Photochemical Reactions ◽  
N2o Emissions ◽  
Secondary Forests ◽  
Soil Emissions ◽  
Amazonian Forests ◽  
The Impact ◽  
No Emissions

This paper reviews reports of nitrous oxide (N2O) and nitric oxide (NO) emissions from soils of the Amazon and Cerrado regions of Brazil. N2O is a stable greenhouse gas in the troposphere and participates in ozone-destroying reactions in the stratosphere, whereas NO participates in tropospheric photochemical reactions that produce ozone. Tropical forests and savannas are important sources of atmospheric N2O and NO, but rapid land use change could be affecting these soil emissions of N oxide gases. The five published estimates for annual emissions of N2O from soils of mature Amazonian forests are remarkably consistent, ranging from 1.4 to 2.4 kg N ha–1 year–1, with a mean of 2.0 kg N ha–1 year–1. Estimates of annual emissions of NO from Amazonian forests are also remarkably similar, ranging from 1.4 to 1.7 kg N ha–1 year–1, with a mean of 1.5 kg N ha–1 year–1. Although a doubling or tripling of N2O has been observed in some young (<2 years) cattle pastures relative to mature forests, most Amazonian pastures have lower emissions than the forests that they replace, indicating that forest-topasture conversion has, on balance, probably reduced regional emissions slightly (<10%). Secondary forests also have lower soil emissions than mature forests. The same patterns apply for NO emissions in Amazonia. At the only site in Cerrado where vegetation measurements have been made N2O emissions were below detection limits and NO emissions were modest (~0.4 kg N ha–1 year–1). Emissions of NO doubled after fire and increased by a factor of ten after wetting dry soil, but these pulses lasted only a few hours to days. As in Amazonian pastures, NO emissions appear to decline with pasture age. Detectable emissions of N2O have been measured in soybean and corn fields in the Cerrado region, but they are modest relative to fluxes measured in more humid tropical agricultural regions. No measurements of NO from agricultural soils in the Cerrado region have been made, but we speculate that they could be more important than N2O emissions in this relatively dry climate. While a consistent pattern is emerging from these studies in the Amazon region, far too few data exist for the Cerrado region to assess the impact of land use changes on N oxide emissions.

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