scholarly journals Production and consumption of nitrous oxide in nitrate-ammonifying Wolinella succinogenes cells

Microbiology ◽  
2014 ◽  
Vol 160 (8) ◽  
pp. 1749-1759 ◽  
Author(s):  
Monique Luckmann ◽  
Daniel Mania ◽  
Melanie Kern ◽  
Lars R. Bakken ◽  
Åsa Frostegård ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrosative Stress ◽  
Stratospheric Ozone ◽  
Anaerobic Respiration ◽  
Model Organism ◽  
Wolinella Succinogenes ◽  
Terminal Electron Acceptor ◽  
Production And Consumption ◽  
Public Consciousness ◽  
Nitrate And Nitrite

Global warming is moving more and more into the public consciousness. Besides the commonly mentioned carbon dioxide and methane, nitrous oxide (N2O) is a powerful greenhouse gas in addition to its contribution to depletion of stratospheric ozone. The increasing concern about N2O emission has focused interest on underlying microbial energy-converting processes and organisms harbouring N2O reductase (NosZ), such as denitrifiers and ammonifiers of nitrate and nitrite. Here, the epsilonproteobacterial model organism Wolinella succinogenes is investigated with regard to its capacity to produce and consume N2O during growth by anaerobic nitrate ammonification. This organism synthesizes an unconventional cytochrome c nitrous oxide reductase (cNosZ), which is encoded by the first gene of an atypical nos gene cluster. However, W. succinogenes lacks a nitric oxide (NO)-producing nitrite reductase of the NirS- or NirK-type as well as an NO reductase of the Nor-type. Using a robotized incubation system, the wild-type strain and suitable mutants of W. succinogenes that either produced or lacked cNosZ were analysed as to their production of NO, N2O and N2 in both nitrate-sufficient and nitrate-limited growth medium using formate as electron donor. It was found that cells growing in nitrate-sufficient medium produced small amounts of N2O, which derived from nitrite and, most likely, from the presence of NO. Furthermore, cells employing cNosZ were able to reduce N2O to N2. This reaction, which was fully inhibited by acetylene, was also observed after adding N2O to the culture headspace. The results indicate that W. succinogenes cells are competent in N2O and N2 production despite being correctly grouped as respiratory nitrate ammonifiers. N2O production is assumed to result from NO detoxification and nitrosative stress defence, while N2O serves as a terminal electron acceptor in anaerobic respiration. The ecological implications of these findings are discussed.

scholarly journals Biological nitrous oxide consumption in oxygenated waters of the high latitude Atlantic Ocean

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Andrew P. Rees ◽  
Ian J. Brown ◽  
Amal Jayakumar ◽  
Gennadi Lessin ◽  
Paul J. Somerfield ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Atlantic Ocean ◽  
High Latitude ◽  
Bacterial Communities ◽  
Stratospheric Ozone ◽  
Intermediate Step ◽  
Anoxic Environments ◽  
Production And Consumption ◽  
Net Flux ◽  
Traditional Understanding

AbstractNitrous oxide (N2O) is important to the global radiative budget of the atmosphere and contributes to the depletion of stratospheric ozone. Globally the ocean represents a large net flux of N2O to the atmosphere but the direction of this flux varies regionally. Our understanding of N2O production and consumption processes in the ocean remains incomplete. Traditional understanding tells us that anaerobic denitrification, the reduction of NO3− to N2 with N2O as an intermediate step, is the sole biological means of reducing N2O, a process known to occur in anoxic environments only. Here we present experimental evidence of N2O removal under fully oxygenated conditions, coupled with observations of bacterial communities with novel, atypical gene sequences for N2O reduction. The focus of this work was on the high latitude Atlantic Ocean where we show bacterial consumption sufficient to account for oceanic N2O depletion and the occurrence of regional sinks for atmospheric N2O.

scholarly journals Nitrous oxide production and consumption: regulation of gene expression by gas-sensitive transcription factors

2012 ◽  
Vol 367 (1593) ◽  
pp. 1213-1225 ◽  
Author(s):  
Stephen Spiro
Keyword(s):  
Nitrous Oxide ◽  
Transcription Initiation ◽  
Regulatory Networks ◽  
Regulation Of Gene Expression ◽  
Environmental Signals ◽  
Production And Consumption ◽  
Genes Encoding ◽  
Nitrous Oxide Production ◽  
Biochemical Mechanisms ◽  
Nitrate And Nitrite

Several biochemical mechanisms contribute to the biological generation of nitrous oxide (N 2 O). N 2 O generating enzymes include the respiratory nitric oxide (NO) reductase, an enzyme from the flavo-diiron family, and flavohaemoglobin. On the other hand, there is only one enzyme that is known to use N 2 O as a substrate, which is the respiratory N 2 O reductase typically found in bacteria capable of denitrification (the respiratory reduction of nitrate and nitrite to dinitrogen). This article will briefly review the properties of the enzymes that make and consume N 2 O, together with the accessory proteins that have roles in the assembly and maturation of those enzymes. The expression of the genes encoding the enzymes that produce and consume N 2 O is regulated by environmental signals (typically oxygen and NO) acting through regulatory proteins, which, either directly or indirectly, control the frequency of transcription initiation. The roles and mechanisms of these proteins, and the structures of the regulatory networks in which they participate will also be reviewed.

scholarly journals Genomic Analysis of Anaerobic Respiration in the Archaeon Halobacterium sp. Strain NRC-1: Dimethyl Sulfoxide and Trimethylamine N-Oxide as Terminal Electron Acceptors

2005 ◽  
Vol 187 (5) ◽  
pp. 1659-1667 ◽  
Author(s):  
Jochen A. Müller ◽  
Shiladitya DasSarma
Keyword(s):  
Dimethyl Sulfoxide ◽  
Regulatory Protein ◽  
Anaerobic Respiration ◽  
Model Organism ◽  
Genomic Analysis ◽  
Oligonucleotide Array ◽  
Transcriptional Unit ◽  
Pcr Analysis ◽  
Phenotypic Analysis ◽  
Terminal Electron Acceptor

ABSTRACT We have investigated anaerobic respiration of the archaeal model organism Halobacterium sp. strain NRC-1 by using phenotypic and genetic analysis, bioinformatics, and transcriptome analysis. NRC-1 was found to grow on either dimethyl sulfoxide (DMSO) or trimethylamine N-oxide (TMAO) as the sole terminal electron acceptor, with a doubling time of 1 day. An operon, dmsREABCD, encoding a putative regulatory protein, DmsR, a molybdopterin oxidoreductase of the DMSO reductase family (DmsEABC), and a molecular chaperone (DmsD) was identified by bioinformatics and confirmed as a transcriptional unit by reverse transcriptase PCR analysis. dmsR, dmsA, and dmsD in-frame deletion mutants were individually constructed. Phenotypic analysis demonstrated that dmsR, dmsA, and dmsD are required for anaerobic respiration on DMSO and TMAO. The requirement for dmsR, whose predicted product contains a DNA-binding domain similar to that of the Bat family of activators (COG3413), indicated that it functions as an activator. A cysteine-rich domain was found in the dmsR gene, which may be involved in oxygen sensing. Microarray analysis using a whole-genome 60-mer oligonucleotide array showed that the dms operon is induced during anaerobic respiration. Comparison of dmsR + and ΔdmsR strains by use of microarrays showed that the induction of the dmsEABCD operon is dependent on a functional dmsR gene, consistent with its action as a transcriptional activator. Our results clearly establish the genes required for anaerobic respiration using DMSO and TMAO in an archaeon for the first time.

The contribution of nitrate respiration to the energy budget of the symbiont-containing clam Lucinoma aequizonata: a calorimetric study

1996 ◽  
Vol 199 (2) ◽  
pp. 427-433
Author(s):  
U Hentschel ◽  
S Hand ◽  
H Felbeck
Keyword(s):  
Heat Production ◽  
Sea Water ◽  
Anaerobic Respiration ◽  
Gill Tissue ◽  
Nitrate Respiration ◽  
Heat Output ◽  
Marine Bivalve ◽  
Calorimetric Study ◽  
Perfusion Medium ◽  
Terminal Electron Acceptor

Heat production and nitrate respiration rates were measured simultaneously in the gill tissue of Lucinoma aequizonata. This marine bivalve contains chemoautotrophic, intracellular, bacterial symbionts in its gill tissue. The symbionts show constitutive anaerobic respiration, using nitrate instead of oxygen as a terminal electron acceptor. An immediate increase in heat production was observed after the addition of nitrate to the perfusion medium of the calorimeter and this was accompanied by the appearance of nitrite in the effluent sea water. The nitrate-stimulated heat output was similar under aerobic and anaerobic conditions, which is consistent with the constitutive nature of nitrate respiration. The amount of heat released was dependent on the concentration of nitrate in the perfusion medium. At nitrate concentrations between 0.5 and 5 mmol l-1, the total heat production was increased over twofold relative to unstimulated baseline values. A mean (±s.e.m.) experimental enthalpy of -130±22.6 kJ mol-1 nitrite (N=13) was measured for this concentration range.

scholarly journals Nitrogen and oxygen availabilities control water column nitrous oxide production during seasonal anoxia in the Chesapeake Bay

2018 ◽  
Vol 15 (20) ◽  
pp. 6127-6138 ◽  
Author(s):  
Qixing Ji ◽  
Claudia Frey ◽  
Xin Sun ◽  
Melanie Jackson ◽  
Yea-Shine Lee ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Chesapeake Bay ◽  
Water Column ◽  
N2o Emissions ◽  
N2o Production ◽  
Isotope Tracer ◽  
Relative Contribution ◽  
Environmental Controls ◽  
Long Run ◽  
Nitrate And Nitrite

Abstract. Nitrous oxide (N2O) is a greenhouse gas and an ozone depletion agent. Estuaries that are subject to seasonal anoxia are generally regarded as N2O sources. However, insufficient understanding of the environmental controls on N2O production results in large uncertainty about the estuarine contribution to the global N2O budget. Incubation experiments with nitrogen stable isotope tracer were used to investigate the geochemical factors controlling N2O production from denitrification in the Chesapeake Bay, the largest estuary in North America. The highest potential rates of water column N2O production via denitrification (7.5±1.2 nmol-N L−1 h−1) were detected during summer anoxia, during which oxidized nitrogen species (nitrate and nitrite) were absent from the water column. At the top of the anoxic layer, N2O production from denitrification was stimulated by addition of nitrate and nitrite. The relative contribution of nitrate and nitrite to N2O production was positively correlated with the ratio of nitrate to nitrite concentrations. Increased oxygen availability, up to 7 µmol L−1 oxygen, inhibited both N2O production and the reduction of nitrate to nitrite. In spring, high oxygen and low abundance of denitrifying microbes resulted in undetectable N2O production from denitrification. Thus, decreasing the nitrogen input into the Chesapeake Bay has two potential impacts on the N2O production: a lower availability of nitrogen substrates may mitigate short-term N2O emissions during summer anoxia; and, in the long-run (timescale of years), eutrophication will be alleviated and subsequent reoxygenation of the bay will further inhibit N2O production.

scholarly journals Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

2010 ◽  
Vol 7 (2) ◽  
pp. 3019-3059 ◽  
Author(s):  
C. H. Frame ◽  
K. L. Casciotti
Keyword(s):  
Nitrous Oxide ◽  
Stratospheric Ozone ◽  
N2o Production ◽  
Isotopic Signatures ◽  
Ammonium N ◽  
O2 Concentration ◽  
Nitrous Oxide Production ◽  
Global Estimates ◽  
Cell Densities ◽  
Ammonia Oxidizing Bacterium

Abstract. Nitrous oxide (N2O) is a trace gas that contributes to greenhouse warming of the atmosphere and stratospheric ozone depletion. The N2O yield from nitrification (moles N2O-N produced/mole ammonium-N consumed) has been used to estimate marine N2O production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O yield from nitrification is not constant. Previous culture-based measurements indicate that N2O yield increases as oxygen (O2) concentration decreases and as nitrite (NO2−) concentration increases. These results were obtained in substrate-rich conditions and may not reflect N2O production in the ocean. Here, we have measured yields of N2O from cultures of the marine β-proteobacterium Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM) media. These yields were lower than previous reports, between 4×10−4 and 7×10−4 (moles N/mole N). The observed impact of O2 concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5×10

scholarly journals Impacts of dietary exposure to sodium or potassium salts of nitrate and nitrite on the development of Drosophila melanogaster

2017 ◽  
Vol 10 (2) ◽  
pp. 70-78 ◽  
Author(s):  
Ashim Kumar Basak ◽  
Tridip Chatterjee ◽  
Swapan Kumar Ghosh ◽  
Amit Chakravarty
Keyword(s):  
Young Adults ◽  
Food Additives ◽  
Polytene Chromosomes ◽  
Model Organism ◽  
Developmental Outcomes ◽  
Dietary Exposure ◽  
Potassium Nitrate ◽  
Toxicological Studies ◽  
Nitrate And Nitrite ◽  
Third Instar Larvae

AbstractThe effects of four food additives, namely sodium nitrite (NaNO2), sodium nitrate (NaNO3), potassium nitrite (KNO2), and potassium nitrate (KNO3), on animal development were evaluated by using Drosophila melanogster, a model organism. Adult male and female flies were allowed to breed in culture medium, each containing one of 4 concentrations,i.e.10, 20, 30 or 40 mM of the above mentioned salts. The concentration of 40 mM, NaNO2and KNO2 completely arrested the development of the flies. Of the different concentrations of the four salts tested, exposure of flies to 30 mM NaNO2exhibited only significant delays in the initial appearances of third instar larvae, pupae and young adults, along with huge reduction in the number of pupae and young adults compared to controls. Rearrangements like inversions, deletion looping, regional shrinking, as well as highly enlarged puffing,etc.were also observed in the polytene chromosomes of the third instar larvae exposed to 30 mM NaNO2. Developmental outcomes of the flies exposed to varying concentrations of NaNO3and KNO3 did not differ significantly from the controls. Owing to the extensive genetic homology between Drosophila and human and the successful uses of this fly as models in developmental and toxicological studies, we speculate that the experimental results exhibited by this organism in our study strongly advocate for abstaining from the dietary use of NaNO2and KNO2 during human pregnancies to avoid possible negative developmental outcomes.

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