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...
Although ammonia-oxidizing archaea (AOA) and bacteria (AOB) coexist in most non-acidic agricultural soils, the factors that influence their relative contributions to soil nitrification activity remain unclear. A 2- to 4-d whole soil microcosm assay was developed, utilizing the aliphatic C₈ alkyne 1-octyne to inactivate AOB-driven nitrification activity without impacting AOA...
Nitrosomonas europaea is a chemolithoautotrophic bacterium that oxidizes ammonia (NH₃) to obtain energy for growth on carbon dioxide (CO₂) and can also produce nitrous oxide (N₂O), a greenhouse gas. We interrogated the growth, physiological, and transcriptome responses of N. europaea to conditions of replete (>5.2 mM) and limited inorganic carbon...
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AndrewGiguere,b Frank Chaplen,c Peter J. Bottomley,b,d Luis A. Sayavedra-Sotoa
Department of Botany and
Nitrosomonas europaea is a chemolithoautotrophic bacterium that oxidizes ammonia (NH₃) to obtain energy for growth on carbon dioxide (CO₂) and can also produce nitrous oxide (N₂O), a greenhouse gas. We interrogated the growth, physiological, and transcriptome responses of N. europaea to conditions of replete (>5.2 mM) and limited inorganic carbon...
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Maintenance and Enhances Nitrous Oxide Production in
Nitrosomonas europaea.
Brett L. Mellbyea#, Andrew
Nitrosomonas europaea is a chemolithoautotrophic bacterium that oxidizes ammonia (NH₃) to obtain energy for growth on carbon dioxide (CO₂) and can also produce nitrous oxide (N₂O), a greenhouse gas. We interrogated the growth, physiological, and transcriptome responses of N. europaea to conditions of replete (>5.2 mM) and limited inorganic carbon...
Nitrosomonas europaea is a chemolithoautotrophic bacterium that oxidizes ammonia (NH₃) to obtain energy for growth on carbon dioxide (CO₂) and can also produce nitrous oxide (N₂O), a greenhouse gas. We interrogated the growth, physiological, and transcriptome responses of N. europaea to conditions of replete (>5.2 mM) and limited inorganic carbon...
Ammonia (NH₃)-oxidizing bacteria (AOB) and thaumarchaea (AOA) co-occupy most soils, yet no short-term growth-independent method exists to determine their relative contributions to nitrification in situ. Microbial monooxygenases differ in their vulnerability to inactivation by aliphatic n-alkynes, and we found that NH₃ oxidation by the marine thaumarchaeon Nitrosopumilus maritimus was unaffected...
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...
Winter climate is expected to change under future climate scenarios, yet the majority of winter ecology research is focused in cold-climate ecosystems. In many temperate systems, it is unclear how winter climate relates to biotic responses during the growing season. The objective of this study was to examine how winter...
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coLin b. fuSS,7 cLare e. kaZanSki,8 juan d. MuñoZ,9 Matthew d. Petrie,1
andrew b. reinMann10 and jane
Amendments and fertilizers applied to optimize crop production and improve soil health also supply inputs of soil organic matter (SOM) and nutrients that affect soil microorganisms. In the dairy-intensive Pacific Northwest, dairy manure is stored as slurry mixtures until conditions are appropriate for soil application. During storage, the manure begins...
Retinoic acid (RA) exerts important effects in the processes of vertebrate development, cellular growth and differentiation, and homeostasis. However, the mechanisms of action of RA in the control of cellular and developmental processes are incompletely understood, as the retinoid target genes have not been fully characterized. The goal of these...
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...
This thesis examines how changes made to the Oregon Health Plan (OHP) in 2003 impacts those now utilizing the emergency room (ER) for primary health care. This thesis also examines how these changes impact staff members working in the ER of Salem Hospital. Through the utilization of qualitative research methods,...
Soil nitrogen exists largely as organic matter, including plant liter, dead animal matter, and microbial necromass. About 90% of soil organic nitrogen is proteinaceous material that is too large for plants and microorganisms to assimilate directly. Protein depolymerization therefore plays a critical role in mobilizing this organic source of nitrogen,...
This dissertation reports on four related, though separate projects. The first project details the process of carrying out a digitally augmented soil mapping (DSM) effort alongside an ongoing survey in Oregon's Ochoco National Forest (ONF) using a Random Forest algorithm. The second chapter describes a initial soil survey in Oregon's...
Deeply weathered soils in tropical rainforests and savannas are classified as Ferralsols according to the World References Bases for Soil Resources (WRB). Ferralsols are most nearly akin to the Oxisols order defined in the US Soil Taxonomy. The acidity, low cation exchange capacity, and strong phosphorus retention by the oxidic...
Forest harvest persists as one of the most globally important industries, and crucially provides raw wood products for both building and fuel materials. Mechanistically complex abiotic and biotic processes curb ecosystem recovery following timber harvest and it is of great importance to understand the effects of this practice on biogeochemical...