Life Sciences Commons^™

Investigating Birds As Dispersal Vectors Of Litylenchus Crenatae Subsp. Mccannii (Anguinidae), The Nematode Associated With Beech Leaf Disease, Spencer Rock Parkinson

Graduate Theses, Dissertations, and Problem Reports

Beech leaf disease (BLD) is an emerging forest pathogen primarily affecting American beech (Fagus grandifolia, Ehrh.) in North America and has been attributed to tree mortality of sapling sized trees within five to seven years of infection. Symptoms typically occur in regenerating American beech thickets sprouting from roots of trees killed by beech bark disease. Scientists first observed BLD in Ohio in 2012 and currently has spread to 15 states in the USA and one Canadian province. The nematode Litylenchus crenatae subsp. mccannii (Lcm) is highly associated with BLD symptoms, interveinal chlorosis and defoliation of leaves, and is currently …

Characterization Of Host Cell Specific Interactions During Spotted Fever Group Rickettsiae Infection, Emerson Towey

Graduate Theses, Dissertations, and Problem Reports

Vector-borne diseases have been increasing over the past few years due to changes in climate and disturbances in the vectors’ natural environment. To mitigate the risks of these diseases, it is necessary to understand pathogen biology and how it interacts with a host to cause disease. Here we focus our attention on the tick-borne pathogen, Rickettsia rickettsii. R. rickettsii is a member of the spotted fever group (SFG) Rickettsiae and is the etiological agent of Rocky Mountain spotted fever (RMSF), a fatal human disease that is lacking an effective vaccine. Members of the bacterial genus Rickettsia are obligate intracellular endoparasites …

Optimizing Sample Collection And Data Interpretation For Effective Wastewater-Based Epidemiology In Combined Sewer Systems, Christopher Allen Anderson

Graduate Theses, Dissertations, and Problem Reports

COVID-19 has spurred growth in the science surrounding wastewater-based epidemiology (WBE) pertaining to the detection of severe acute respiratory virus 2 (SARS-CoV-2) in waste streams as an early warning signal for public health. However, the highly variable wastewater environment has made it difficult to standardize an approach for sampling and analysis, especially in locations using combined sewer infrastructure. This study addresses knowledge gaps of WBE via three specific aims: (1) to compare diurnal fluctuations of SARS-CoV-2 and the human fecal indicator, pepper mild mottle virus (PMMoV) in wastewater treatment plant (WWTP) influent samples collected during dry versus wet weather conditions; …

Extension Of The Ergot Alkaloid Gene Cluster, Samantha Joy Fabian

Graduate Theses, Dissertations, and Problem Reports

Specialized metabolites produced by fungi impact human health. A large portion of the pharmaceuticals currently on the market are derived from metabolites biosynthesized by microbes. Ergot alkaloids are a class of fungal metabolites that are important in the interactions of environmental fungi with insects and mammals and also are used in the production of pharmaceuticals. In animals, ergot alkaloids can act as partial agonists or antagonists at receptors for 5-hydroxytryptamine (serotonin), dopamine, and noradrenaline as ergot alkaloids have chemical structures similar to those neurotransmitters. Therefore, they affect insects and mammals that consume them and can be used to produce drugs …

Evaluating Innovative Methods Of Quantitatively Linking Microbial Community Structure To Ecosystem Function, Jeth Gv Walkup

Graduate Theses, Dissertations, and Problem Reports

Microbial functional diversity is the product of community structure and intraspecific trait variation. Due to microbial diversity and limited availability of microbial trait measurements, it has been challenging to quantitatively link community structure to microbial function. Although community-level activity rates vary with community composition, issues in the scale of their measurement inhibit our understanding of their relationship. Quantitative stable isotope probing (qSIP) is a method for quantitatively measuring taxon-specific microbial traits, providing new opportunities to apply trait-based approaches for studying microbial ecology. Quantitative microbial trait data from these experiments enables the functional characterization of microbial communities, potentially enabling the extrapolation …

Survival Of Listeria Monocytogenes On Organic Honeycrisp And Fuji Apples During Storage At 5, 12 And 22.5◦C, Connor S. Freed

Graduate Theses, Dissertations, and Problem Reports

This study aimed to evaluate and model the survival of Listeria monocytogenes on organic HoneyCrisp (HC) and Fuji (FJ) apples during storage at various temperatures. Fresh organic HC and FJ apples (without wax coating) obtained from a local wholesale market were inoculated with a 2-strain mix of L. monocytogenes followed by storage at 5.0 (22.9% RH), 12.0 (37.0% RH), and 22.5oC (50.4% RH) for 60, 35, 7 days, respectively, and periodically (day-0 to 60) analyzing microbial populations. Surviving L. monocytogenes were spread-plated on Modified-Oxford agar after 10 or 100-fold serial dilution. Data were analyzed using the mixed-model procedure of SAS …

Attachment Issues: Microbes, Minerals, And The Persistence Of Soil Organic Matter, Md Shafiul Islam Rion

Graduate Theses, Dissertations, and Problem Reports

The remnants of microorganisms are now understood to account for the majority of organic matter in many mineral soils. Despite the significance of this microbial necromass for soil carbon storage, we know relatively little about how the traits of microorganisms interact with soil minerals to determine the stability of microbe derived carbon in soil. Soil minerals differ in their surface area and chemistry potentially influencing microbial attachment, biofilm formation, and the persistence of microbial necromass. To address this knowledge gap, we grew twelve bacterial species from four broad groups of varying cell wall morphology (Gram positive, Gram negative, filamentous actinobacteria, …

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 …

Utilizing The K18-Hace2 Mouse Model To Develop Protective Covid-19 Vaccines, Ting Y. Wong

Graduate Theses, Dissertations, and Problem Reports

The ongoing Coronavirus Disease 2019 (COVID-19) pandemic is caused by the respiratory virus Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Similar to other respiratory viruses, SARS-CoV-2 is transmitted through inhalation of respiratory droplets and aerosols from infected individuals. Once inhaled, SARS-CoV-2 utilizes the receptor binding domain (RBD) on the spike protein to bind to human Angiotensin Converting Enzyme 2 (hACE2) receptor to gain entrance into host cells to begin viral replication. SARS-CoV-2 infection can result in mild to severe cases of COVID-19 ranging from asymptomatic infections, cold or flu like symptoms to respiratory failure. The onset of the pandemic in …

Evaluate The Efficacy Of A Mixture Of Peroxyacetic Acid And H2o2 Against The Survival And Cross-Contamination Of The Salmonella Surrogate Enterococcus Faecium On Tomatoes During Triple-Wash, Corey Waitman Coe

Graduate Theses, Dissertations, and Problem Reports

Triple-wash with a mixture of peroxyacetic acid and H2O2 (SaniDate-5.0) during post-harvest processing of fresh produce has been recommended by West Virginia Small Farm Center to improve microbial safety. It has been well recognized that the washing of produce is more important for preventing cross-contamination than reducing foodborne pathogens. Furthermore, it may help improve public confidence in that the produce they obtain from locally grown farmers is safe for their consumption. determine the efficacy of SaniDate-5.0 for reducing the survival and preventing cross-contamination of the Salmonella surrogate Enterococcus faecium on tomatoes during triple-wash.

E. faecium ATCC-8459 (resistant to 100-ppm nalidixic-acid) …

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 …

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 …

Effects Of Biofertilizer On Soil Nutrient Cycling And The Productivity Of Bioproduct Crops In Marginal Soils, Kieran B. Liseski

Graduate Theses, Dissertations, and Problem Reports

Recently there has been increased interest in the use of marginal lands in order to grow bioproduct crops. Utilizing marginal lands to grow bioproduct crops such as Miscanthus x giganteus and Panicum virgatum could not only improve soil quality and minimize negative environmental impacts on the surrounding ecosystems but could also offer economic benefits to growers in rural areas. Because marginal soils tend to reduce crop yields compared to prime farmlands even when growing bioproduct crops, which tend to be more robust than traditional food crops, augmenting the soil with biofertilizers (i.e., the direct addition of viable microbial cells) could …

A Snapshot Of Ancient Microbial Life: Microorganisms And Organic Compounds In Primary Fluid Inclusions In Bedded Halite, Neoproterozoic Browne Formation Of Central Australia, Sara I. Schreder-Gomes

Graduate Theses, Dissertations, and Problem Reports

Modern shallow brine environments contain an abundance of microorganisms. Microorganisms, mineral crystals, and air bubbles can be trapped with those brines in primary fluid inclusions in bedded halite as it grows in shallow saline surface waters. Primary fluid inclusions and their contents can be preserved, unaltered, for millions of years.

The ~830 million-year-old Browne Formation of central Australia contains intervals of bedded halite with unaltered primary fluid inclusions. Intervals of bedded halite were sampled in the Empress 1A core from ~1480 m – 1520 m depths. Here, I used petrography to describe suspect microorganisms and organic compounds that were trapped …

Tree Species Influence On Microbial Functional Gene Abundance And N Cycling In Riparian Soil, Elizabeth Matejczyk

Graduate Theses, Dissertations, and Problem Reports

Little is known about how above-ground vegetation may differentially influence the below-ground microbial community structure, abundance, and function. Abundance of soil microbial N cycling genes responsible for nitrification (amoA), denitrification (nirK and nirS), and nitrous oxide reduction (nosZ) may vary with tree species and increasing N availability, and these variables may be used to predict production of NO₃^- and N₂O from soil. Variability of nitrification and denitrification rates have also been linked to tree mycorrhizal associations, with soil beneath tree species associated with arbuscular mycorrhizal (AM) exhibiting greater denitrification rates …

Initial And Advanced Stages Of Microbiota Establishment Within The Tsetse Fly, Miguel Eduardo Medina Munoz

Graduate Theses, Dissertations, and Problem Reports

Symbiosis is a long-term physical association between two or more species, although little is known regarding its evolutionary origins, particularly at the genetic level. Tsetse flies are the vector of African trypanosomes, causative agents of Human and Animal African Trypanosomiases. Tsetse provide an ideal model for studying initial and advanced stages of symbiosis. Tsetse have a simple digestive tract microbiota primarily consisting of two bacteria; the ancient mutualist Wigglesworthia glossinidia and the recently acquired Sodalis glossinidius. This work presents a chronological study in evolutionary terms of the history of a microbial-insect association. First, I present concepts on symbiosis and …

Pseudomonas Aeruginosa Vaccine Development Using Dual-Species Whole Cell And Subunit Vaccines, Catherine Bell Blackwood

Graduate Theses, Dissertations, and Problem Reports

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen which can cause severe, recurrent, and chronic infections. The pathogen is highly adaptable, and pneumonia caused by it is associated with high morbidity and mortality, especially in individuals with the genetic disorder cystic fibrosis. Antibiotic resistance amongst clinical isolates of P. aeruginosa is steadily increasing, and multi-drug resistant strains are prevalent. There is currently no vaccine available for commercial use against P. aeruginosa. For these reasons, we sought to understand the immunity to P. aeruginosa induced by whole cell vaccination and identify antigens for development of future subunit vaccines. In this dissertation, …

Genetic And Biochemical Characterization Of Ergot Alkaloid Synthesizing Fungi And Their Symbionts, Matthew Duane Maust

Graduate Theses, Dissertations, and Problem Reports

Ergot alkaloids are fungal tryptophan derived toxins which affect mammalian circulation and neurotransmission. These compounds are biosynthesized by a conserved genetic pathway, known as the ergot alkaloid synthesis (EAS) pathway by fungi belonging to the ascomycete families Trichocomaceae and Clavicipitaceae. Several Ipomoea species and related plants in the morning glory family harbor vertically transmitted symbiotic fungi in the genus Periglandula, also members of Clavicipitaceae, that produce ergot alkaloids. Metabolomic analysis of seeds identified a previously uncharacterized glycoside form of the pharmaceutically important ergot alkaloid, ergonovine. Several species belonging to the fungal genus Metarhizium have recently been shown to have the …

Microbial Responses To Unconventional Oil And Gas Development May Alter Ecosystem Function In Headwater Streams, Rachel Michaels

Graduate Theses, Dissertations, and Problem Reports

The demand for natural gas, and the need for efficient extraction, has led to the development of unconventional oil and natural gas (UOG) techniques. Due to the novelty of UOG, the potential impacts to freshwater ecosystems are not fully understood. We used a dual pronged approach to study the effects of UOG development on microbial biodiversity and function via a laboratory microcosm experiment and a survey study of streams with and without UOG development within their watersheds. The laboratory microcosm study simulated stream contamination with produced water, a byproduct of UOG operation, using sediment collected from one high water-quality stream …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

The Host Gatekeeper: Using The Flagellar Pathway To Understand Symbiont Host Adaptation, Adam R. Pollio

Graduate Theses, Dissertations, and Problem Reports

The acquisition of microbial partners is a strategy used by a diverse group of arthropods to overcome ecological barriers that might normally make certain niches uninhabitable. The unique phylogenetic opportunities attainable from the natural experiment of the Sodalis-allied clade allow for better understanding of how molecular structures evolve through time. Here, we focus on the evolution of the flagellar synthesis pathway, due to its complexity and ability to diverge in response to ecological pressures. We used this molecular pathway and natural experiment to show that normal evolutionary outcomes associated with symbiosis (i.e., genome reduction) do not explain the predicted conservation …

Soil Microbial Succession Following Surface Mining Is Governed Primarily By Deterministic Factors, Jennifer Lynne Kane

Graduate Theses, Dissertations, and Problem Reports

Understanding the successional dynamics governing soil microbial community assembly is a promising way to advance development of remediation strategies for lands disturbed by anthropogenic activities. The environmental and ecological influences shaping these communities following soil disturbance remain only partially understood. One example of a physical anthropogenic disturbance is extraction of minerals such as coal by surface mining. Surface mining removes natural soils and these soils may be replaced immediately on adjacent reclaimed areas or they may be stored in piles for later use. During reclamation, the soil is replaced on the landscape and the site is re-vegetated with grasses and …

Mine Reclamation Using Biofuel Crops: Insights Into The Microbial Ecology Of The Switchgrass (Panicum Virgatum) Microbiome, Brianna L. Mayfield

Graduate Theses, Dissertations, and Problem Reports

Bioenergy crop production has steadily increased due to growing political support for renewable energy, thus initiating a demand to find alternative agricultural land. An innovative option is the use of marginal soils, such as reclaimed mine lands, to produce bioenergy crops. Switchgrass (Panicum virgatum) is a promising bioenergy crop that can be grown on marginal lands due to its robust growth in various soil types and climates. However, little is known regarding plant-microbe interactions among switchgrass systems within reclaimed mine lands. A study conducted in 2008 grew switchgrass on high- and low- quality reclaimed mine sites (Hampshire and …

Adaptation Of The Streptococcal Collagen-Like Protein 1, Scl1, Of Group A Streptococcus To Recognize Fibronectin Type Iii Repeats, Dudley H. Mcnitt

Graduate Theses, Dissertations, and Problem Reports

Background: Group A Streptococcus (GAS) is responsible more than 700 million infections worldwide each year. Most of these infections start with initial colonization of the throat and skin, which is augmented by surface adhesins. The streptococcal collagen-like protein 1 (Scl1) is a major adhesin expressed by GAS that contains an N-terminal sequence-variable (V) domain, protruded away from the cell surface by the collagen domain. The Scl-V domain is comprised of three pairs of anti-parallel α-helices interconnected by surface-exposed loops. For attachment, GAS adhesins require a portal of entry, such as a wound or breach in the epithelium, to enter …

Crop Rotations That Integrate Pasture Are Less Vulnerable To Nitrogen Leaching Due To Changes In Microbial Community Composition And Reduced Nitrification, Jeth Gv Walkup

Graduate Theses, Dissertations, and Problem Reports

Agroecosystems occupy a large portion of the United States and receive a disproportionally high amount of terrestrial nitrogen inputs. As application rates increase, nitrogen use efficiency declines leading to higher rates of nitrogen loss. To develop sustainable agricultural practices, the long-term effects of management practices on the soil microorganisms that perform central roles in the transformation of nitrogen need to be studied. To study the long-term impacts of compost application and pasture integration in crop rotation, samples were collected from the existing 19-year-old Organic Crop Livestock Field (OCLF) experiment on the WVU organic research farm. The OCLF experiment includes a …