Life Sciences Commons^™

Biological Remediation Of Fragipan, Corey Hale

Honors College Theses

The fragipan layer in the soil is a naturally occurring subsurface layer that restricts water percolation as well as inhibits root growth. A fragipan layer can be found almost ubiquitously across Southwestern Kentucky. This limits how agriculturalists manage soils in this area. It has been recently discovered by the University of Kentucky that Annual Ryegrass roots produce 3,4 dihydroxyphenylpropionic acid (DHPPA) that reacts with this hardpan to weaken the layer. Certain bacteria, such as Escherichia coli, Lactobacilli, and Bifidobacteria can also synthesize DHPPA through a breakdown process of chlorogenic acid. This reaction typically happens in the human digestive tract. …

Evaluation Of The Selected Nuproxa Feed Additives For Protection Against Lameness And Improving The Wellbeing Of Broilers In The Lameness Challenge Model, Abigail Fanous

Biological Sciences Undergraduate Honors Theses

Bacterial Chondronecrosis with Osteomyelitis (BCO) is a form of bacteria that causes lameness in broiler chickens and is a common concern within the poultry industry. This easily transmissible disease can quickly take over entire livestock of chickens leading to an animal welfare issue. Due to this, it is a pressing issue that must be solved in order to protect the wellbeing of broiler chickens and ensure viable livestock. Nuproxa is a company that specializes in chicken feed in which we used to test different amounts of Panbonis, a dietary supplement, in its effectiveness in protecting broiler chickens against BCO lameness. …

Coastal Stormwater Pond Pollutants And The Potential For Development Of Antimicrobial Resistance In Vibrio And Enterococcus Bacteria, Cassandra L. Horton

Theses and Dissertations

The Southeastern coastal plain is the most rapidly urbanizing region in the United States. Associated landscape changes which increase imperviousness lead to hydrological cycle alterations, increasing runoff of nonpoint source (NPS) pollution. Urban and agricultural NPS runoff is generally discharged into stormwater ponds, which sequester chemical contaminants, nutrients, and microbes to reduce loading into coastal ecosystems. Studies of these ponds have indicated elevated levels of trace metals, antimicrobial compounds, and bacterial contamination (SCSGC 2018).

Interactions of aquatic pathogens Vibrio vulnificus and Enterococcus faecium with trace metals (arsenic, copper, zinc) and clinically relevant antimicrobials (triclosan, ciprofloxacin, oxytetracycline) commonly found in coastal …

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 …

Implications Of Antibiotic And Bacteriophage Resistance In Environmentally Isolated E. Coli, Michael Connolly

Honors Theses

The increasing prevalence of antibiotic-resistant bacteria is an emerging problem for humans. Clinical misuse, overuse in agricultural and food settings, and limited numbers of new antibiotics have accelerated the proliferation of antibiotic-resistant bacteria. To confront this threat, scientists must develop new therapeutics that kill these antibiotic-resistant bacteria. In this study, we used Escherichia coli to analyze antibiotic and bacteriophage susceptibility. E. coli is a common, mostly benign, enteric, gram-negative bacteria. We isolated three E. coli strains from the Hans Groot Kill, a stream that runs through Union College’s campus. We sought to assess various E. coli strains’ antibiotic resistance, susceptibility …

Assembly Of The Peripheral Arm Subunits Of Escherichia Coli Complex I And Analysis Of Clinical Mutations, Hind Alkhaldi

Biological Sciences Theses and Dissertations

Respiratory Complex I from E. coli is a proto-type of the mitochondrial enzyme, consisting of a 6-subunit peripheral arm (B-CD-E-F-G-I) and a 7-subunit membrane arm. When subunits E-F-G (N-module), were expressed alone they formed an active complex as determined by co-immunoprecipitation and native gel electrophoresis. When co-expressed with subunits B and CD, only a complex of E-F-G was found. When these five subunits were co-expressed with subunit I and two membrane subunits, A and H, a complex of B-CD-E-F-G-I was membrane-bound, constituting the N- and Q-modules. Assembly of Complex I was also followed by splitting the genes between two plasmids, …

Antibiotic-Resistant Bacteria In Freshwater Crayfish, Colby Finch

Honors Theses

The presence of antibiotic-resistant bacteria is increasing in natural aquatic environments. Alongside this, organisms that live in these ecosystems are increasingly harboring antibiotic-resistant bacteria. In this study, I analyzed the capacity for the crayfish species Procambarus vioscai paynei to harbor antibiotic-resistant bacteria. Crayfish, as well as water and sediment, were sampled from a pond at the University of Mississippi Field Station. The guts of crayfish were plated on TSA agar, as well as agar containing vancomycin, erythromycin, penicillin, tetracycline, or ciprofloxacin. Following incubation, counts of bacteria were determined. Selected bacterial isolates were tested for multiple antibiotic-resistance. Bacterial isolates were also …

A Comparison Of Heterotroph Isolation And Sequencing Methods From Various Cyanobacterial And Algal Microbiomes, Victoria Starks

Honors Theses

Cyanobacteria have provided a vast, new source of natural products to be utilized in drug development. Because of their non-axenic nature, cyanobacteria typically have an abundance of symbiotic heterotrophs living in association with them. These bacteria can play significant roles in the survival of its cyanobacterial host as well as provide the potential production of unique compounds. The possibility of unknown natural products is only increased by the flexible nature of these bacteria, as altering its environmental state can change the activity of biosynthetic pathways and even activate novel production. Our research team’s intent is to isolate cyanobacterial strains from …

To The Window, To The Wall: Improving Environmental Monitoring Protocols, Sarah Jones

Graduate Theses and Dissertations

Detecting microorganisms on environmental surfaces via an environmental monitoring (EM) program is part of a preventive food safety culture. Environmental monitoring should 1) verify that food safety plans are reducing cross-contamination risk from surfaces to food, 2) pinpoint microbial niches, and 3) prevent the transmission of pathogens. Environmental monitoring programs utilize EM tools, such as sponges, to sample food contact and non-food contact surfaces. However, EM tool selection is determined by the individual food firm. This dissertation evaluated and characterized factors influencing EM program effectiveness in the food industry. Specifically, this dissertation focuses on the release of microorganisms from EM …

Analysis And Identification Of Lipolytic Bacterial Species For The Degradation Of Wastewater Lipids, Lindsay C. Smoak

Honors College Theses

The aim of this study was to isolate native bacterial strains from the wastewater treatment facilities of Statesboro, GA to identify their lipolytic activities. Obtained bacterial strains were further assessed via morphological and biochemical methods to determine their enzymatic capabilities. Use of the detergent Tween-20 in growth mediums was the first criteria to assess lipase activity, and these isolates were further investigated to quantitatively measure lipase presence and activity. Lipase protein was precipitated and dialyzed to perform a lipase activity assay, followed by Sodium Dodecyl Sulphate–Polyacrylamide Gel Electrophoresis (SDS-PAGE) to confirm the presence of the lipolytic enzymes. Sanger sequencing was …

Links Between Electrophilic Stress And Antifungal Resistance In Pathogenic Candida Species, Amy R. Biermann

Dartmouth College Ph.D Dissertations

Collectively, Candida species are the most prevalent cause of both superficial and invasive fungal infections worldwide. Invasive Candida infections have a high mortality rate and predominantly affect individuals with underlying diseases, such as diabetes, HIV, or cancer. Unfortunately, many invasive Candida infections are recalcitrant to antifungal treatment, while intrinsically multidrug-resistant pathogens, like Candida auris, are increasing in prevalence. Although the canonical mechanisms of antifungal resistance in Candida species are well established, i.e., overexpression of efflux pumps and overexpression of or mutations in genes encoding drug targets, factors affecting the natural evolution and regulation of resistance mechanisms remain poorly understood. …

Microbial Community And Soil Responses To Land Management Practices In Remnant And Restored Tallgrass Prairies, Desirae Marie Klimek

Graduate Research Theses & Dissertations

Critical ecosystem functions, such as decomposition and nutrient cycling, are driven by microbial communities within soil. As such, it is important to examine the effect of restoration practices, such as the presence of native grazers and prescribed burning, on these microbes and the soil they inhabit. The Nachusa Grasslands provides a chronosequence of restored tallgrass prairies ranging in restoration age from 5 to 33 years, as well as remnant prairies, and agricultural fields. These sites were sampled seasonally from 2013-2020 and microbial ribosomal RNA genes were surveyed to characterize soil microbial communities and assess how common restoration practices affect these …

Identification, Enumeration, And Diversity Determinations For Fungi Enriched On Phthalates As Sole Carbon Source From Riverine Sediments Using Molecular Methods, Anthony M. Vicidomini

All Capstone Projects

Phthalates are a common chemical compound used as plasticizers in various industries that have been linked to several detrimental effects on health. Due to their widespread use, they have become a common environmental pollutant of soil and water. The persistence and distribution of phthalate esters in the environment has given rise to many microorganisms that are able to incorporate phthalates into various metabolic pathways and degrade them into harmless substances, with fungi being among those that are capable of such degradation of industrial polycyclic aromatic hydrocarbons. In this study, the diversity of fungal communities in response to the presence of …

Inhibition Of Staphylococcus Aureus Biofilm By Variovorax Paradoxus, Esther Gomez

University of the Pacific Theses and Dissertations

Staphylococcus aureus is one of the leading causes of fatal nosocomial infections. Often, S. aureus can grow as a biofilm which protects the population from the surrounding environment. Strains of S. aureus are resistant to virtually all known antibiotics on the market. Variovorax paradoxus is a soil microbe with many unusual metabolic activities. It has been previously observed that, V. paradoxus can inhibit the growth of S. aureus when in co-culture. In this work we report on inhibition of S. aureus biofilm formation by V. paradoxus due to a suspected inhibitory soluble factor.

Microbial Community Analysis: Biofilm Inhibition & Algae Associated Community Structure, Michelle V. Fong

University of the Pacific Theses and Dissertations

Natural products chemistry is the pursuit of bioactive small molecules from living organisms. These can be classified as primary metabolites if they are essential to survival, and secondary metabolites if they are accessory, playing a role in communication, defense, recruitment, etc.. Natural products have made a significant contribution to society – of 1,881 FDA-approved drugs from 1981 to 2019, 4% were pure natural products, 19% were natural products derived, and 3% were synthetic drugs with a natural products pharmacophore targeting a wide range of diseases and infections (Newman & Cragg, 2020). Pharmacophores are structural components of drugs that are responsible …

Ifn-Γ Increases The Expression Of Sars-Cov-2 Receptors On Vero E6 Cells, Bindu Madhavi Madabattula

Browse all Theses and Dissertations

Respiratory epithelial cells are the initial target for SARS-CoV-2 infection. IFN-γ is known to increase the expression of ACE-2, an initial receptor for SARS-CoV-2, on epithelial cells. This study focuses on examining the effect of IFN-γ for ACE-2, TMPRSS2, and neuropilin-1 on Vero E6 cells using two immunofluorescence methods, namely, direct (membrane) fluorescence method and Cytation5 method. Direct fluorescence was determined using an Accu-Scope and ImageJ analysis. Using this method, significance (p<0.023) was observed only for ACE-2 when Vero E6 cells were treated with IFN-γ. Cytation5 fluorescence was determined using a Bio-tek Cytation5 plate reader. The results showed that IFN-γ significantly increased (p<0.001) the expression of ACE-2, neuropilin-1, and TMPRSS2. These results indicate Cytation5 is a more sensitive method for determining the expression of receptors on Vero E6 cells. The elevated levels of SARS-CoV-2 receptors expression resulting from IFN-γ treatment makes the epithelial cells more susceptible targets of SARS-CoV-2 infection. IFN-γ is most likely provided by innate immune cells in the initial COVID-19 infection, consequently contributing to the severity of disease.

The Bgs 13 Mutant Of Pichia Pastoris And Its Effect On Structural Changes Of The Reporter Protein B-Lactogolbulin, Bushra Irshad

University of the Pacific Theses and Dissertations

Pichia pastoris, a methylotrophic yeast, is an ideal host for recombinant protein expression. It has the capability of performing many eukaryotic post-translational modifications and grows to high cell densities. However, P. pastoris’s secretion properties are not always efficient, and its secretory pathway mechanisms have not been thoroughly elucidated. A previously identified mutant strain, bgs13, was found to efficiently secrete most recombinant proteins tested, raising the possibility that this bgs13 mutant is a universal super secreter and understanding its secretion process is needed. In this study, we used a reporter protein, ?-lactoglobulin (b-LG), to perform structural analysis and comparisons of protein …

Reconstruction Of Gut Microbiome Via Intermittent Feeding, Kourtney Sprague

Browse all Theses and Dissertations

The benefits of intermittent fasting have been studied across many facets of health. It is known that physiologically fasting results in a metabolic switch from liver-derived glucose to adipose cell derived ketones to be used as energy and signaling molecules. Fasting down-regulates inflammation, increases expression of antioxidant defenses, and activates pathways for DNA repair and autophagy. While fasting or intermittent feeding effects on host physiology have been identified, the relationship between fasting and gut microbiome is not as well known. In times of gut rest, resident microbes undergo detoxication and motility, and in times of activity, gut microbes undergo DNA …

Impact Of Orthophosphate As A Corrosion Inhibitor And Chloramine Disinfectant On Drinking Water Biofilm Communities, Mitchell Cooke

Theses and Dissertations (Comprehensive)

A drinking water distribution system (DWDS) must maintain conditions within quality standards which assure the effective and safe transport of finished drinking water from treatment plants to the household tap. Although safe to drink, finished water is not sterile, and may contain hundreds of microorganisms in a single milliliter. These microorganisms are present from the source waters, such as lakes, rivers and aquifers, and have passed through early treatment steps. Final treatment steps, such as the maintenance of disinfectant residuals, are used to further minimize viable cells present and focus on the reduction of harmful organisms. Microbial cells entering the …