The coupling of nitrification and denitrification in two estuarine sediments1,2

Jenkins, Mark C.; Kemp, William

doi:10.4319/lo.1984.29.3.0609

Cited by 385 publications

(231 citation statements)

References 15 publications

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“…Denitrification is recognised to be limited by NO 3 -supplies and hence by nitrification in coastal sediments (Jenkins and Kemp, 1984). In our study, nitrification is the main source of NO 3 -for denitrification, with an average Dn rate contribution reaching 98 % of Dt rate at 12 o C. Since Dn was statistically correlated to temperature, this result suggests that the coupling between nitrification and denitrification is thermo-dependant and consequently could be more important under summer than winter conditions in a cold salt marsh environment.…”

Section: Discussionmentioning

confidence: 99%

Seasonal variability of denitrification efficiency in northern salt marshes: An example from the St. Lawrence Estuary

Poulin

Pelletier

Saint-Louis

2007

Marine Environmental Research

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Section: Discussionmentioning

confidence: 99%

Seasonal variability of denitrification efficiency in northern salt marshes: An example from the St. Lawrence Estuary

Poulin

Pelletier

Saint-Louis

2007

Marine Environmental Research

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“…Il permet d'une part la régénération des formes oxydées de l'azote et d'autre part, lorsqu'il est couplé à la dénitrification dans les sédiments, il favorise l'élimination d'azote du milieu (JENKINS & KEMP, 1984 ;RYSGAARD et al, 1993 ;JENSEN et al, 1996 ; entre autres). Pour bien comprendre et quantifier les flux d'azote dans ces environnements, la mesure de l'activité nitrifiante (taux d'oxydation d'ammonium et/ou de nitrites) ainsi que le dénombrement de ces micro-organismes sont des étapes obligées.…”

Section: Introductionunclassified

Une réévaluation de la methode d'incorporation de H14C03- pour mesurer la nitrification autotrophe et son application pour estimer des biomasses de bactéries nitrifiantes

Brion¹,

Billen²

2005

rseau

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Le processus de nitrification joue un rôle essentiel dans le cycle de l'azote dans les milieux aquatiques naturels. La mesure de l'activité nitrifiante est une étape obligée pour bien comprendre et quantifier les flux d'azote dans ces milieux. Ce travail présente une réévaluation de la méthode de mesure de l'activité nitrifiante autotrophe par la méthode d'incorporation de bicarbonate marqué au 14C et son application pour estimer des biomasses de bactéries nitrifiantes. La validité générale de la méthode a été démontrée par des tests menés sur des inhibiteurs de nitrification qui ont montré que l'utilisation combinée de N-serve (5 ppm) et de chlorate (10 mM) inhibait de manière complète et spécifique l'oxydation d'azote et l'incorporation de carbone des deux groupes de bactéries nitrifiantes. Un facteur de rendement (carbone incorporé par azote oxydé) de 0,1 mole C/mole N a également été déterminé sur des cultures pures de bactéries nitrosantes et nitratantes. Pour l'activité potentielle, en particulier, les conditions optimales pour la mesure d'activité nitrifiante ont également été établis: un pH entre 7 et 8, une température entre 20 et 30°C, une concentration en ammonium d'au moins 1 mmol/l et en oxygène d'au moins 6 mg/l. Une relation entre les mesures d'activité nitrifiante potentielle et la biomasse des bactéries nitrifiantes a été établie sur culture pure. Elle montre que dans les conditions de mesures de l'activité potentielle, 1 µg C de bactéries nitrifiantes oxyde 0,04 µmol N/hBy regenerating oxidised forms of nitrogen (nitrate), the nitrification process plays an important role in the nitrogen cycle of aquatic environments. The measurement of the activity and biomass of nitrifying bacteria is thus essential to understand and quantify the general nitrogen fluxes in those environments. Different methods of measuring the nitrifying activity exist. The first methods developed were based on the use of specific nitrification inhibitors: N-serve, allyl thio-urea, acetylene, methylfluoride and dimethyl ether, as most used. They consist in measuring differences of ammonium, nitrite and nitrate dynamics in an inhibited and control sample during time. These methods can be applied as long as the inhibitors are specific for nitrifying bacteria, and activities are high enough to allow the measurement of concentration variations during incubation times which are not too long. At the present time, the most used methods are dealing with isotopic tracers: 14C or 15N. 15N methods allow the direct measurement of the nitrifying activity, while 14C methods represent the measurement of a biomass production which can be converted into a substrate oxidation rate by the use of a yield factor. This factor is considered to be constant in the standard incubation conditions. The most frequently used enumeration methods of nitrifying bacteria are not very satisfactory. Classical culture techniques (most probable number) and immunofluorescence techniques are known to greatly underestimate the numbers of active organisms. Recently de...

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“…The predictive relationship between SOD and DNF is likely applicable to other low nitrate coastal systems. This is due in part to the close coupling between nitrification and DNF in coastal ecosystems, where ambient nitrate concentrations are low (Jenkins andKemp 1984, Seitzinger 1988). Seitzinger et al (2006) suggested systems with nitrate concentrations below 10 lm will have primarily coupled nitrification-denitrification, and thus the potential for a predictive relationship between DNF and SOD.…”

Section: Relationship Of Dnf and Sodmentioning

confidence: 99%

Habitat-specific distinctions in estuarine denitrification affect both ecosystem function and services

2011

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Abstract. Resource limitation controls the base of food webs in many aquatic ecosystems. In coastal ecosystems, nitrogen (N) has been found to be the predominant limiting factor for primary producers. Due to the important role nitrogen plays in determining ecosystem function, understanding the processes that modulate its availability is critical. Shallow-water estuarine systems are highly heterogeneous. In temperate estuaries, multiple habitat types can exist in close proximity to one another, their distribution controlled primarily by physical energy, tidal elevation and geomorphology. Distinctions between these habitats such as rates of primary productivity and sediment characteristics likely affect material processing. We used membrane inlet mass spectrometry to measure changes in N 2 flux (referred to here as denitrification) in multiple shallow-water estuarine habitats through an annual cycle. We found significantly higher rates of denitrification (DNF) in structured habitats such as submerged aquatic vegetation, salt marshes and oyster reefs than in intertidal and subtidal flats. Seasonal patterns were also observed, with higher DNF rates occurring in the warmer seasons. Additionally, there was an interaction between habitat type and season that we attributed to the seasonal patterns of enhanced productivity in individual habitat types. There was a strong correlation between denitrification and sediment oxygen demand (SOD) in all habitats and all seasons, suggesting the potential to utilize SOD to predict DNF. Denitrification efficiency was also higher in the structured habitats than in the flats. Nitrogen removal by these habitats was found to be an important contributor to estuarine ecosystem function. The ecosystem service of DNF in each habitat was evaluated in US dollars using rates from a regional nutrient-offset market to determine the cost to replace N through management efforts. Habitat-specific values of N removal ranged from approximately three thousand U.S. dollars per acre per year in the submerged aquatic vegetation to approximately four hundred U.S. dollars per acre per year in the subtidal flat. Because of the link between habitat type and processes such as DNF, changes in habitat area and distribution will have consequences for both ecosystem function and the delivery of ecosystem services.

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The coupling of nitrification and denitrification in two estuarine sediments1,2

Cited by 385 publications

References 15 publications

Seasonal variability of denitrification efficiency in northern salt marshes: An example from the St. Lawrence Estuary

Seasonal variability of denitrification efficiency in northern salt marshes: An example from the St. Lawrence Estuary

Une réévaluation de la methode d'incorporation de H14C03- pour mesurer la nitrification autotrophe et son application pour estimer des biomasses de bactéries nitrifiantes

Habitat-specific distinctions in estuarine denitrification affect both ecosystem function and services

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