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- Graduate Theses, Dissertations, and Problem Reports (3)
- Plant and Soil Sciences Faculty Publications (3)
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- Doctoral Dissertations (2)
- Electronic Thesis and Dissertation Repository (2)
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- Masters Theses (2)
- All Master's Theses (1)
- Chancellor’s Honors Program Projects (1)
- Dartmouth Scholarship (1)
- Geofrey Soka (1)
- Historical Research Bulletins of the Nebraska Agricultural Experiment Station (1)
- LSU Master's Theses (1)
- OES Faculty Publications (1)
- Pursuit - The Journal of Undergraduate Research at The University of Tennessee (1)
- School of Biological Sciences: Faculty Publications (1)
- Theses and Dissertations (1)
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Articles 1 - 24 of 24
Full-Text Articles in Life Sciences
Isolating And Characterizing Lipid Degrading Microbes From Human Decomposition Soils, Brooke Amara Talley, Allison R. Mason, Jennifer Debruyn
Isolating And Characterizing Lipid Degrading Microbes From Human Decomposition Soils, Brooke Amara Talley, Allison R. Mason, Jennifer Debruyn
Chancellor’s Honors Program Projects
No abstract provided.
Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones
Effects Of Mass Death On Community Structure And Ecosystem Function, Abby Kimpton Jones
Theses and Dissertations
Death and decomposition are natural processes that are generally well-understood. However, large events of death, such as mass mortality events (MMEs) are increasing in frequency and their impacts on the ecosystem are largely unknown. These events may have both bottom-up effects from increased nutrient input as well as top-down effects from loss of an ecological functional group by the affected population. Different functional MMEs may result in different top-down effects, creating cascading effects. In Chapter 1, I test the hypothesis that scavenger and herbivore simulated MMEs generate novel bottom-up and top-down effects. Results indicate that MMEs have a significant effect …
Making Sense Of Soil Microbiome Complexity For Plant And Ecosystem Function In A Changing World, Kendall K. Beals
Making Sense Of Soil Microbiome Complexity For Plant And Ecosystem Function In A Changing World, Kendall K. Beals
Doctoral Dissertations
Soils contain the highest biodiversity on Earth. While the importance of the soil microbiome for larger-scale ecological phenomena such as nutrient and carbon cycling, plant growth and plant community dynamics is well-established, the fundamental question of the ecological and evolutionary function of this immense belowground microbial diversity for plant and ecosystem function still remains a great challenge in microbial ecology research. The objective of this dissertation is to understand how the importance of soil microbial community composition for plant and ecosystem function and how changes to soil microbial community composition from climate change-induced disturbance events, specifically fire, influence plant and …
Cross-Kingdom Interactions Shape Soil Biogeochemistry In Natural And Agricultural Ecosystems, Jennifer Lynne Kane
Cross-Kingdom Interactions Shape Soil Biogeochemistry In Natural And Agricultural Ecosystems, Jennifer Lynne Kane
Graduate Theses, Dissertations, and Problem Reports
Microorganisms influence life on earth in innumerable ways, including in medical, industrial, environmental, and agricultural contexts. Given the increasingly apparent consequences of climate warming, interest in how to better predict and manage Earth’s carbon sinks has never been greater. Soil, the largest terrestrial carbon sink, harbors an incredibly taxonomically and functionally diverse microbial community. These soil-dwelling microbes govern the fate of soil carbon and nutrients by cycling organic matter as they live, grow, and die. It has only been relatively recently that technological advancement has allowed for in-depth surveys of the vast diversity of soil microbes. High throughput analytical capabilities …
Anthropogenic Disturbance Regimes Impact The Microbial And Chemical Composition Of Soils And Sediments Across Ecosystems, Gregory D. Martin
Anthropogenic Disturbance Regimes Impact The Microbial And Chemical Composition Of Soils And Sediments Across Ecosystems, Gregory D. Martin
Graduate Theses, Dissertations, and Problem Reports
Human activities have led to profound changes in the climate and environment, fundamentally changing global carbon and nitrogen cycles. Ongoing conversion of wildland for human use and the intensification of agricultural systems have dire consequences for biodiversity and the ecosystem services that support society. While natural disturbance regimes are important for the long-term maintenance of native biodiversity and ecosystem function, many disturbances are becoming increasingly frequent due to anthropogenic activities. Increasing the frequency, intensity, or duration of disturbances can prevent ecosystems from returning to their previous equilibria. Disturbance-induced changes to the local environment shape microbial communities, which in turn govern …
Response Of The Soil Bacterial Community, Resistome, And Mobilome To A Decade Of Macrolide Antibiotic Contamination, Liam Paul Brown
Response Of The Soil Bacterial Community, Resistome, And Mobilome To A Decade Of Macrolide Antibiotic Contamination, Liam Paul Brown
Electronic Thesis and Dissertation Repository
Biosolids (treated sewage sludge) are used as agricultural fertilizer but are frequently contaminated with macrolide antibiotics, to which resistance is rising among historically susceptible bacteria. To determine if the land-application of macrolides carried in biosolids could promote antibiotic resistance in soil bacteria, soil plots were exposed annually to environmentally realistic or high doses of macrolides for ten years. I sequenced the bacterial 16S ribosomal DNA, metagenomic DNA, and integron gene cassettes within the treated and antibiotic-free soil to compare the compositions and diversities of the bacterial communities, antibiotic resistance genes, and mobile genetic elements. I determined that the high dose …
Effects Of Traditional And Microbially-Focused Restoration Techniques On Soil Communities In Tallgrass Prairies, Zachary J. Whitacre
Effects Of Traditional And Microbially-Focused Restoration Techniques On Soil Communities In Tallgrass Prairies, Zachary J. Whitacre
Masters Theses
Tallgrass prairies have virtually disappeared in many parts of their former range due to the conversion of this ecosystem to farmland. In more recent years there have been efforts to restore these prairies on reclaimed agricultural land. However, these restored prairies do not resemble their remnant counterparts in many ways, such as in soil microbial community composition and metrics related to carbon storage. In Chapter 1, I show that bacterial communities in a restored prairie and an adjacent remnant prairie in southwest Michigan differ in their immediate and longer-term responses to prescribed fire, a commonly used prairie restoration and maintenance …
Distribution, Diversity, And Biogeography Of Anaerobic Carbon Monoxide Uptake By Microbial Communities In Soils And Sediments, Amber N. Depoy
Distribution, Diversity, And Biogeography Of Anaerobic Carbon Monoxide Uptake By Microbial Communities In Soils And Sediments, Amber N. Depoy
LSU Master's Theses
Carbon monoxide (CO) is primarily known for being a toxic gas. However, CO is used by microorganisms as an electron or carbon source in a variety of respiratory processes. Different kinds of microorganisms utilize CO aerobically and anaerobically, using two distinct CO dehydrogenases (CODHs). Aerobes oxidize CO using a molybdenum-dependent dehydrogenase (Mo-CODH), while anaerobes utilize a nickel-dependent CO dehydrogenase (Ni-CODH). Studies of the biochemistry and microbiology of aerobic and anaerobic CO oxidation are extensive, but relatively little is known about the ecology of anaerobic CO oxidation. In an effort to test new hypotheses about the ecology of anaerobic CO oxidation, …
Determining The Effects Of Imidacloprid On Non-Target Soil Organisms In Hemlock Stands, Braley Burke
Determining The Effects Of Imidacloprid On Non-Target Soil Organisms In Hemlock Stands, Braley Burke
Graduate Theses, Dissertations, and Problem Reports
The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an invasive insect that is causing mortality of eastern hemlock trees, Tsuga canadensis, and Carolina hemlock trees, Tsuga caroliniana, across the eastern United States. To protect these ecologically important tree species, a neonicotinoid insecticide, imidacloprid, is commonly used. Imidacloprid is an effective treatment and can remain effective against HWA for four to six years but long-term (≥ one year after application) non-target effects of imidacloprid on forest ecosystems are not well-studied. This study examined terrestrial non-target effects of imidacloprid in hemlock stands with different treatment histories to …
Diversity Analysis Of Soil Fungus Communities In Disturbed, Nursery, And Mature Forest Conditions, Dana Whitmore
Diversity Analysis Of Soil Fungus Communities In Disturbed, Nursery, And Mature Forest Conditions, Dana Whitmore
All Master's Theses
Populations of soil fungi were examined in Derby Canyon Natives, Coeur d’Alene Forest Service nursery, Swamp Lake, and the Keechelus Lake wildlife overcrossing soils. All sampling sites were connected by their relation to the revegetation and native soil plug inoculation of the wildlife overpass. This study was an effort to describe soil fungi communities present on the overpass before plant introduction, those that plants would be bringing in their pots, and the fungi that could be introduced via soil plug transplantation. DNA was extracted from soil samples, then sequenced using next-generation sequencing methods, allowing for the analysis of species richness …
Changes In Soil Microbial Communities After Long-Term Warming Exposure, William G. Rodríguez-Reillo
Changes In Soil Microbial Communities After Long-Term Warming Exposure, William G. Rodríguez-Reillo
Doctoral Dissertations
Microbial metabolism is a key controller of ecosystem processes (e.g., carbon cycling). However, we are only starting to identify the molecular mechanisms and feedback in response to long-term warming. My dissertation integrates multi-omics techniques to capture changes in soil microbial communities after long-term warming exposure. The research projects leverage three warming sites (i.e., SWaN, Barre Woods, and Prospect Hill) located in Western Massachusetts at Harvard Forest. These sites provided a unique experimental setup to better understand microbes in response to long-term temperature change. For the three research projects, we delved into the (i) microbial biodiversity across all three warming sites, …
A Survey Of Β-Lactam Antibiotic Resistance Genes And Culturable Ampicillin Resistant Bacteria In Minnesota Soils, Emily M. Wollmuth
A Survey Of Β-Lactam Antibiotic Resistance Genes And Culturable Ampicillin Resistant Bacteria In Minnesota Soils, Emily M. Wollmuth
Departmental Honors Projects
Since the discovery of penicillin, antibiotics have been an essential tool in the treatment of bacterial infections and diseases. It is estimated that antibiotics and antibiotic resistance genes have existed for billions of years. With the increasing appearance of resistant pathogenic bacteria, there has been growing concern. β-lactam antibiotics make up the largest portion of the global market, so resistance to these antibiotics is especially alarming. It has been theorized that frequency and type of antibiotic resistance genes vary by area. Previous studies suggest that these differences may be related to antibiotic use in agricultural and urban areas. To survey …
Antibiotic Resistance Genes In Minnesota Soil Bacteria From Areas Of High And Low Ferric Iron, Gunner L. Drossel, Presley Martin Phd
Antibiotic Resistance Genes In Minnesota Soil Bacteria From Areas Of High And Low Ferric Iron, Gunner L. Drossel, Presley Martin Phd
Departmental Honors Projects
Naturally-occurring antibiotic resistance genes in soil bacteria represent a potentially important reservoir of genes that could contribute to antibiotic resistance of human pathogens. It has been reported that over 40 genes in bacterial genomes are controlled by concentrations of ferric iron. We examined the effect of soil metal content on the level of resistance to two antibiotics, ampicillin (Amp) and tetracycline (Tet), and the presence of multiple genes that code for efflux pump-mediated resistance. These pumps act to export toxins (e.g. heavy metals and antibiotics, perhaps). Because of this, growth in heavy metal-contaminated soils might select for antibiotic resistance. Ninety-six …
Influence Of Current Land Use And Edaphic Factors On Arbuscular Mycorrhizal (Am) Hyphal Abundance And Soil Organic Matter In And Near Serengeti National Park, Geofrey Soka, Mark Ritchie, Emilian Mayemba
Influence Of Current Land Use And Edaphic Factors On Arbuscular Mycorrhizal (Am) Hyphal Abundance And Soil Organic Matter In And Near Serengeti National Park, Geofrey Soka, Mark Ritchie, Emilian Mayemba
Geofrey Soka
Arbuscular mycorrhizal fungi (AMF) are important microbial symbionts for plants especially when soil phosphorus (P) and nitrogen (N) are limited. Little is known about the distribution of AM hyphae in natural systems of tropical soils across landscapes and their association with different land uses. We studied mycorrhizal hyphal abundance in a wildlife grazed system, a livestock grazed system and under cultivated soils in and near Serengeti National Park, Tanzania. Samples of the upper 15 cm of soil beneath locally dominant plant species were collected. Hyphae were preserved on permanent slides and the length of hyphae per cubic centimeter of soil …
Response Of Soil Nitrification To The Veterinary Pharmaceuticals Monensin, Ivermectin And Zinc Bacitracin, Magda A. Konopka
Response Of Soil Nitrification To The Veterinary Pharmaceuticals Monensin, Ivermectin And Zinc Bacitracin, Magda A. Konopka
Electronic Thesis and Dissertation Repository
Pharmaceutical residues can reach agricultural land through amendment with animal or human waste. Since 2010, a series of replicated plots received annual applications of ivermectin, monensin and zinc bacitracin, either singly or in a mixture, at 0.1 mg/kg and 10 mg/kg concentrations. I collected soil samples before and after the fourth annual application of pharmaceuticals and assayed them for functional changes and amoA gene abundance, a gene needed for ammonia oxidation. In 2013, I exposed the soils to 100 mg/kg in a laboratory experiment which resulted in acceleration of nitrification. Under 10 mg/kg treatments in the field the abundance of …
Revealing The Ecological Role Of Gemmatimonadetes Through Cultivation And Molecular Analysis Of Agricultural Soils, Mariam Naomi Fawaz
Revealing The Ecological Role Of Gemmatimonadetes Through Cultivation And Molecular Analysis Of Agricultural Soils, Mariam Naomi Fawaz
Masters Theses
Bacteria belonging to phylum Gemmatimonadetes are frequently detected in a variety of environments using culture-independent methods. Despite their ubiquity and prevalence, almost nothing is known about their physiology or ecology because so few strains have been isolated. The first objective of this study was to determine the distribution of Gemmatimonadetes within soil aggregates and the response of the relative abundance of Gemmatimonadetes to dry/wet cycling and soil management. The second objective was to analyze the effects of soil management, aggregate size, and atmospheric conditions on cultivability of Gemmatimonadetes. Universal and Gemmatimonadetes-specific 16S rRNA gene primers were used to …
Respiration And Carbon Dioxide Accumulation In Soil Microcosms, Jasity Murphy
Respiration And Carbon Dioxide Accumulation In Soil Microcosms, Jasity Murphy
Pursuit - The Journal of Undergraduate Research at The University of Tennessee
The thawing of permafrost leads to liberation of soil organic matter and microbial component resulting in significant effect on the carbon cycle. Changes in permafrost soils upon the global climate warming would significantly impact microbial soil activity. Currently, not a great deal is known about what happens to the microbial community after the permafrost thaws. The activity of microbial community was determined in microcosms experiment using respirometry. To assess the CO2 fluctuations during permafrost thawing a titration experiment was performed. Based on calculations using the respirometric equation it was found that CO2 production increases with temperature, core depth, …
Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan
Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan
School of Biological Sciences: Faculty Publications
Soil microbial diversity is vast, and we lack even basic understanding of how this diversity is distributed ecologically. Using pyrosequencing and microarray methods, we quantified the structure of bacterial communities in two contrasting soils underlying Bornean rain forest (clay and sandy loam) that differ markedly in soil properties, aboveground tree flora, and leaf litter decomposition rates. We found significant soil-related taxonomic and phylogenetic differences between communities that, due to their proximity, are independent of climate. Bacterial communities showed distinct compositional and taxon-abundance distributions that were significantly correlated with the structure of the overlying tree community. Richness of bacteria was greater …
Cellulose- And Xylan-Degrading Thermophilic Anaerobic Bacteria From Biocompost, M. V. Sizova, J. A. Izquierdo, N. S. Panikov, L. R. Lynd
Cellulose- And Xylan-Degrading Thermophilic Anaerobic Bacteria From Biocompost, M. V. Sizova, J. A. Izquierdo, N. S. Panikov, L. R. Lynd
Dartmouth Scholarship
Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S …
Soil Microbial Community Response To Hexavalent Chromium In Planted And Unplanted Soil, Ioannis Ipsilantis, Mark S. Coyne
Soil Microbial Community Response To Hexavalent Chromium In Planted And Unplanted Soil, Ioannis Ipsilantis, Mark S. Coyne
Plant and Soil Sciences Faculty Publications
Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation extraction and soil extract ATP, tolerance to Cr and growth rates with tritiated thymidine incorporation, and performed community substrate use analysis with BIOLOG GN plates. Exchangeable Cr(VI) levels were very low, and therefore we assumed the Cr(VI) impact was transient. Microbial biomass was reduced …
Effects Of Commercial Diazinon And Imidacloprid On Microbial Urease Activity In Soil And Sod, C. W. Ingram, Mark S. Coyne, David W. Williams
Effects Of Commercial Diazinon And Imidacloprid On Microbial Urease Activity In Soil And Sod, C. W. Ingram, Mark S. Coyne, David W. Williams
Plant and Soil Sciences Faculty Publications
Diazinon [O,O-diethyl O-2-isopropyl-6-methyl(pyrimidine-4-yl) phosphorothioate] and imidacloprid [1-(1-[6-chloro-3-pyridinyl]methyl)-N-nitro-2-imidazolidinimine] are applied to lawns for insect control simultaneously with nitrogenous fertilizers such as urea, but their potential effect on urease activity and nitrogen availability in turfgrass management has not been evaluated. Urease activity in enzyme assays, washed cell assays, and soil slurries was examined as a function of insecticide concentration. Intact cores from field sites were used to assess the effect of insecticide application on urease activity in creeping bentgrass (Agrostis palustris Huds.) and bluegrass (Poa pratensis L.) sod. Bacterial urease fromBacillus pasteurii and plant …
Nitrous Oxide Loss From Poultry Manure-Amended Soil After Rain, Mark S. Coyne, A. Villalba, Robert L. Blevins
Nitrous Oxide Loss From Poultry Manure-Amended Soil After Rain, Mark S. Coyne, A. Villalba, Robert L. Blevins
Plant and Soil Sciences Faculty Publications
Land application of poultry wastes in Kentucky will increase as the broiler industry grows. If poultry manure stimulates N2O loss from soil it will reduce the fertilizer N value of this waste. In contrast, stimulated N2O loss in grass filter strips receiving the runoff from manured fields could help reduce contamination of surface water by NO−3. Our objectives were to determine (i) if poultry manure stimulated N2O loss in soil after rainfall and (ii) if there was an edge-of-field effect on N2O loss in grass filters intercepting runoff from …
A Comparison Of No And N20 Production By The Autophic Nitrifier Nitrosomonas Europaea And The Heterotrophic Nitrifier Alcaligenes Faecalis, Iris C. Anderson, Mark Poth, Julie Homstead, David J. Burdige
A Comparison Of No And N20 Production By The Autophic Nitrifier Nitrosomonas Europaea And The Heterotrophic Nitrifier Alcaligenes Faecalis, Iris C. Anderson, Mark Poth, Julie Homstead, David J. Burdige
OES Faculty Publications
Soil microorganisms are important sources of the nitrogen trace gases NO and N2O for the atmosphere. Present evidence suggests that autotrophic nitrifiers such as Nitrosomonas europaea are the primary producers of NO and N2O in aerobic soils, whereas denitrifiers such as Pseudomonas spp. or Alcaligenes spp. are responsible for most of the NO and N2O emissions from anaerobic soils. It has been shown that Alcaligenes faecalis, a bacterium common in both soil and water, is capable of concomitant heterotrophic nitrification and denitrification. This study was undertaken to determine whether heterotrophic nitrification might be …
Distribution Of Microorganisms In The Soil As Affected By Plowing And Subtilling Crop Residues, Roy C. Dawson, Virginia T. Dawson, T. M. Mccalla
Distribution Of Microorganisms In The Soil As Affected By Plowing And Subtilling Crop Residues, Roy C. Dawson, Virginia T. Dawson, T. M. Mccalla
Historical Research Bulletins of the Nebraska Agricultural Experiment Station
The purpose of this investigation was primarily to determine what effects rate and method of application of residues have on the distribution of microorganisms within the plow-depth layer of soil.