Snowbrush (Ceanothus velutinus), red alder (Alnus rubra), and
bitterbrush (Purshia tridentata) are three important nitrogen- fixing
nonleguminous species. They commonly grow in association with
commercially important conifers in western United States and conceivably
could be utilized to add nitrogen to forest ecosystems. Nitrogen
15 gas was used to study nitrogen...
The role of nitrate oxygen as a terminal acceptor of hydrogen
stands as a unique form of bacterial respiration. As nitrate is reduced
to nitrite on to the gaseous state (N₂, N₂O) the substrate is
oxidized to give the requisite energy for cell growth. The present
study will deal with...
When nitrate is used in a biological electron transport
system as the final acceptor of hydrogen to form water,
the system is characterized as "Nitrate Respiration." However,
the quantitative expression of the over-all participation
of NO₃⁻(0) in the oxidation of glucose by denitrifiers
such as Pseudomonas stutzeri deserves clarification.
In...
Denitrification is classically defined as the microbial reduction
of nitrate and nitrite with the liberation of molecular nitrogen
and, in some instances, nitrous oxide. The sequence of reactions
in which nitrogen is evolved as an end-product is essentially a
respiratory mechanism in which nitrate and/or nitrite replaces
molecular oxygen. The...
Chloride containing fertilizers are used to reduce the severity of take-all root rot of wheat in western Oregon and appear to reduce nitrification in moderately acid soils. Objectives of this study were to determine if nitrification is inhibited by the Cl ion, increasing soil solution ionic strength, or changes in...
Published June 1914. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
In most environments, ammonia (NH₃) is oxidized to nitrate (NO₃⁻) via the intermediate nitrite (NO₂⁻). This is a microbe-driven process involving phylogenetically distinct types of microorganisms, namely, ammonia-oxidizing bacteria (AOB) and Thaumarchaea (AOA), and nitrite-oxidizing bacteria (NOB). Nitrosomonas europaea and Nitrobacter winogradskyi are the best studied AOB and NOB, respectively,...
The chemolithoautotrophic nitrite oxidizing bacteria (NOB) participate in the
biogeochemical cycling of nitrogen by catalyzing and conserving energy from the
oxidation of nitrite (NO₂-) to nitrate (NO₃-) via a nitrite oxidoreductase (NXR). The
main objective of this work was to comparatively annotate and analyze the genome
sequences of Nitrobacter winogradskyi...
Due to the effective antimicrobial properties of silver nanoparticles they represent a significant proportion of all consumer-‐related nanomaterials. The introduction of silver nanoparticles from these products into domestic and industrial wastewater streams poses potential complications for biological treatment systems. A critical component of biological treatment that is extremely sensitive to...
Nitrosomonas europaea carries out the first step in the biological nitrogen removal process in wastewater treatment by oxidizing ammonia to nitrite. It has been shown to be sensitive to a wide range of contaminants. The antibiotic oxytetracycline and the heavy metals chromium and silver have been found in wastewater influent....
The objectives of this thesis were to examine the links between soil microbial community composition and function using the nitrogen (N) cycle as a model for these interactions and to assess the impact of environmental factors such as microclimate, vegetation type, and nutrient availability on microbial diversity and N transformations...
Nitrification is a critical step in the global nitrogen cycle involving the biological oxidation of ammonia (NH₃) to nitrite (NO₂⁻ ) and then to nitrate (NO₃⁻). The first step in nitrification is carried out by NH₃-oxidizing bacteria (AOB) and archaea (AOA), and the second by NO₂⁻-oxidizing bacteria (NOB). In addition...
A year-long, bench-scale treatability study was performed to assess whether an activated sludge sequencing batch reactor could be used to treat an influent stream of 50/50 (v/v) municipal wastewater and landfill leachate to discharge standards established by the Oregon Department of Environmental Quality. One primary obstacle that was exposed during...
Nitrification is the process within the global Nitrogen Cycle where ammonia (NH3) is oxidized to nitrate (NO₃⁻) and can be carried out by two distinct groups of bacteria. The ammonia-oxidizing bacteria (AOB) first oxidize NH₃ to nitrite (NO₂⁻), and second, the nitrite-oxidizing bacteria (NOB) oxidize NO₂⁻ to NO₃⁻. In aerobic...
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Luis A. Sayavedra-Soto
Nitrification is the process within the global Nitrogen Cycle where
Three rates of urea, urea-DCD, and NH₄N0₃ were soil applied in April and August 1986 to strawberry selection OR-US 4930 and cultivar 'Sumas' to determine effects of the nitrification inhibitor dicyandiamide (DCD) and nitrogen source and rate on soil NH₄ and N0₃ levels, fruit yield and quality, and mineral composition...
Silver nanoparticles are increasingly being incorporated into consumer products due to their broad-spectrum antimicrobial properties. The resulting influx of silver nanoparticles into wastewater may pose a threat to bacteria involved in biological wastewater treatment. Ammonia-oxidizing bacteria, which convert ammonia to nitrite in the first step of nitrification, are highly sensitive...
Nitrification and denitrification are major biological processes transforming nitrogen (N) in soils to plant available N, highly leachable nitrate (NO₃⁻) and gaseous N oxides. Although many studies in the past have studied N cycling communities, the effect of increased N inputs on ammonia-oxidizer and denitrifier population dynamics is still under...
In recent years considerable interest has been shown in the diversity of ammonia-oxidizing bacteria in soil communities. The majority of the research has been carried out in Northern Europe where soils have received high atmospheric inputs of nitrogen over the past two centuries. In contrast, although much work has been...
Prior to 2005, ammonia oxidation, the first step of nitrification, was thought mediated mainly by ammonia-oxidizing bacteria (AOB). However, the discovery of Thaumarchaeota carrying the genes coding for the ammonia monooxygenase (AMO) enzyme led to the discovery that ammonia-oxidizing archaea (AOA) also contribute to nitrification. Despite the uptick in studies...