Furnace formation of silicon oxynitride thin dielectrics in nitrous oxide (N2O): The role of nitric oxide (NO)

1994 ◽  
Vol 75 (3) ◽  
pp. 1811-1817 ◽  
Author(s):  
Philip J. Tobin ◽  
Yoshio Okada ◽  
Sergio A. Ajuria ◽  
Vikas Lakhotia ◽  
William A. Feil ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Silicon Oxynitride ◽  
Thin Dielectrics

Role of Nitric Oxide in the Thermal Decomposition of Nitrous Oxide

1956 ◽  
Vol 25 (1) ◽  
pp. 106-115 ◽  
Author(s):  
Frederick Kaufman ◽  
Norman J. Gerri ◽  
Roger E. Bowman
Keyword(s):  
Nitric Oxide ◽  
Thermal Decomposition ◽  
Nitrous Oxide ◽  
Decomposition Of Nitrous Oxide

Model-based evaluation of the role of Anammox on nitric oxide and nitrous oxide productions in membrane aerated biofilm reactor

2013 ◽  
Vol 446 ◽  
pp. 332-340 ◽  
Author(s):  
Bing-Jie Ni ◽  
Barth F. Smets ◽  
Zhiguo Yuan ◽  
Carles Pellicer-Nàcher
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Biofilm Reactor ◽  
Model Based

scholarly journals Nitric Oxide Signaling and Transcriptional Control of Denitrification Genes in Pseudomonas stutzeri

2001 ◽  
Vol 183 (8) ◽  
pp. 2516-2526 ◽  
Author(s):  
Kai-Uwe Vollack ◽  
Walter G. Zumft
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Insertional Mutagenesis ◽  
Pseudomonas Stutzeri ◽  
Threshold Concentration ◽  
Signal Molecules ◽  
Low Oxygen ◽  
Nitric Oxide Signaling ◽  
Transcriptional Pattern

ABSTRACT The expression of denitrification by a facultatively anaerobic bacterium requires as exogenous signals a low oxygen tension concomitant with an N oxide. We have studied the role of nitric oxide (NO), nitrous oxide (N2O), and nitrite as signal molecules for the expression of the denitrification apparatus ofPseudomonas stutzeri. Transcriptional kinetics of structural genes were monitored by Northern blot analysis in a 60-min time frame after cells were exposed to an N oxide signal. To differentiate the inducer role of NO from that of nitrite, mRNA kinetics were monitored under anoxic conditions in a nirFstrain, where NO generation from nitrite is prevented because of a defect in heme D1 biosynthesis. NO-triggered responses were monitored from the nirSTB operon (encoding cytochromecd 1 nitrite reductase), the norCBoperon (encoding NO reductase), nosZ (encoding nitrous oxide reductase), and nosR (encoding a putative regulator). Transcription of nirSTB and norCB was activated by 5 to 50 nM NO, whereas the nosZ promoter required about 250 nM. Nitrite at 5 to 50 nM elicited no response. At a threshold concentration of 650 nM N2O, we observed in the anoxic cell the transient appearance of nosZ and nosRtranscripts. Constant levels of transcripts of both genes were observed in an anoxic cell sparged with N2O. NO at 250 nM stimulated in this cell type the expression of nos genes severalfold. The transcription factor DnrD, a member of the FNR-CRP family, was found to be part of the NO-triggered signal transduction pathway. However, overexpression of dnrD in an engineered strain did not result in NirS synthesis, indicating a need for activation of DnrD. NO modified the transcriptional pattern of the dnrD operon by inducing the transcription of dnrN and dnrO, located upstream of dnrD. Insertional mutagenesis ofdnrN altered the kinetic response of the nirSTBoperon towards nitrite. Our data establish NO and DnrD as key elements in the regulatory network of denitrification in P. stutzeri. The NO response adds to the previously identified nitrate-nitrite response mediated by the NarXL two-component system for the expression of respiratory nitrate reductase encoded by thenarGHJI operon.

scholarly journals Denitrifying metabolism of the methylotrophic marine bacteriumMethylophaga nitratireducenticrescensstrain JAM1

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e4098 ◽  
Author(s):  
Florian Mauffrey ◽  
Alexandra Cucaita ◽  
Philippe Constant ◽  
Richard Villemur
Keyword(s):  
Nitric Oxide ◽  
Nitrous Oxide ◽  
Isotopic Labeling ◽  
Gene Clusters ◽  
No Production ◽  
Gene Encoding ◽  
Anoxic Conditions ◽  
Denitrification Reactor ◽  
Denitrification Genes

BackgroundMethylophaga nitratireducenticrescensstrain JAM1 is a methylotrophic, marine bacterium that was isolated from a denitrification reactor treating a closed-circuit seawater aquarium. It can sustain growth under anoxic conditions by reducing nitrate (${\mathrm{NO}}_{3}^{-}$) to nitrite (${\mathrm{NO}}_{2}^{-}$). These physiological traits are attributed to gene clusters that encode two dissimilatory nitrate reductases (Nar). Strain JAM1 also contains gene clusters encoding two nitric oxide (NO) reductases and one nitrous oxide (N2O) reductase, suggesting that NO and N2O can be reduced by strain JAM1. Here we characterized further the denitrifying activities ofM. nitratireducenticrescensJAM1.MethodsSeries of oxic and anoxic cultures of strain JAM1 were performed with N2O, ${\mathrm{NO}}_{3}^{-}$ or sodium nitroprusside, and growth and N2O, ${\mathrm{NO}}_{3}^{-}$, ${\mathrm{NO}}_{2}^{-}$ and N2concentrations were measured. Ammonium (${\mathrm{NH}}_{4}^{+}$)-free cultures were also tested to assess the dynamics of N2O, ${\mathrm{NO}}_{3}^{-}$ and ${\mathrm{NO}}_{2}^{-}$. Isotopic labeling of N2O was performed in15NH4+-amended cultures. Cultures with the JAM1ΔnarG1narG2double mutant were performed to assess the involvement of the Nar systems on N2O production. Finally, RT-qPCR was used to measure the gene expression levels of the denitrification genes cytochromebc-type nitric oxide reductase (cnorB1andcnorB2) and nitrous oxide reductase (nosZ), and alsonnrSandnorRthat encode NO-sensitive regulators.ResultsStrain JAM1 can reduce NO to N2O and N2O to N2and can sustain growth under anoxic conditions by reducing N2O as the sole electron acceptor. Although strain JAM1 lacks a gene encoding a dissimilatory ${\mathrm{NO}}_{2}^{-}$ reductase, ${\mathrm{NO}}_{3}^{-}$-amended cultures produce N2O, representing up to 6% of the N-input. ${\mathrm{NO}}_{2}^{-}$ was shown to be the key intermediate of this production process. Upregulation in the expression of cnorB1,cnorB2, nnrSandnorRduring the growth and the N2O accumulation phases suggests NO production in strain JAM1 cultures.DiscussionBy showing that all the three denitrification reductases are active, this demonstrates thatM. nitratireducenticrescensJAM1 is one of many bacteria species that maintain genes associated primarily with denitrification, but not necessarily related to the maintenance of the entire pathway. The reason to maintain such an incomplete pathway could be related to the specific role of strain JAM1 in the denitrifying biofilm of the denitrification reactor from which it originates. The production of N2O in strain JAM1 did not involve Nar, contrary to what was demonstrated inEscherichia coli.M. nitratireducenticrescensJAM1 is the only reportedMethylophagaspecies that has the capacity to grow under anoxic conditions by using ${\mathrm{NO}}_{3}^{-}$ and N2O as sole electron acceptors for its growth. It is also one of a few marine methylotrophs that is studied at the physiological and genetic levels in relation to its capacity to perform denitrifying activities.

A critical role of iNOS-derived Nitric Oxide (NO) and progesterone in implantation

1998 ◽  
Vol 5 (1) ◽  
pp. 115A-115A
Author(s):  
K CHWALISZ ◽  
E WINTERHAGER ◽  
T THIENEL ◽  
R GARFIELD
Keyword(s):  
Nitric Oxide ◽  
Critical Role
Sign in / Sign up

Export Citation Format

Share Document