Microbiology Commons^™

Effect Of Dietary Flavonoids On Growth In Saccharomyces Cerevisiae, Vivian Rivera

Mahurin Honors College Capstone Experience/Thesis Projects

Plant foods contain a diversity of biologically active compounds called phytochemicals, produced by plant species as secondary metabolites. A phytochemical group known as flavonoids has received much scientific attention in recent times with respect to their antioxidative and anti-inflammatory roles. This investigation examined how quercetin and naringenin, the most common dietary flavonoids, affect growth potential of yeast under optimal and stress conditions (temperature, glucose, and oxidative stress). Using Saccharomyces cerevisiae as a model, a dose dependency effect of quercetin and naringenin was observed under optimal conditions when liquid cultures were treated with three different concentrations (75 μM, 150 μM, and …

Screening And Analysis Of The Urobiome For The Production Of Antimicrobial Peptides To Target Uropathogenic Escherichia Coli, Jennifer Jones

Theses

Urobiome research is currently at a nascent stage, due to a previously incorrect assumption that the bladder is a sterile environment. Improvements in bacterial culturing and DNA sequencing techniques have revealed a diverse resident bacterial community within the urinary tract (urobiome). As global incidences of multidrug- resistant urinary tract infections (UTIs) continue to increase, so too does the demand for novel antimicrobial therapies. Due to its relatively understudied nature, the urobiome represents a reservoir that could be mined as a potential source of novel antimicrobial compounds (e.g., bacteriocins). The aim of this thesis was to identify urobiome bacteriocins that could …

Contributions Of The Replication Initiator Protein Dnaa To Physiology And Virulence Of The Lyme Disease Spirochete, Andrew Krusenstjerna

Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics

Borrelia burgdorferi, the etiological agent of Lyme disease, is the most prevalent vector-borne disease in the United States. The spirochetal population is naturally maintained by consistently cycling between Ixodid ticks and small vertebrates. To survive within these diverse niches, B. burgdorferi has evolved a unique physiology and regulatory network to sense and respond to environmental fluxes. Replication is a hallmark of the Lyme spirochete’s enzootic life cycle, specifically at the nymphal tick-to-vertebrate interface. The mechanisms and regulatory schema for the basic cellular processes in B. burgdorferi, or indeed any member of the phylum spirochaetota, are largely unknown. The central hypothesis …

Role Of Autophagy-Related Genes In Lipid Transport For Efficient Replication Of Tombusviruses, Yuanrong Kang

Theses and Dissertations--Plant Pathology

Tombusviruses are positive-strand RNA viruses, which utilize numerous co-opted host factors and massive de-novo synthesized membrane resources to modify host membranes and form large viral replication organelles (VROs). Among plenty of host cellular processes, autophagy emerges as a potential membrane resource for VROs formation due to its ability to de-novo generate the double membrane structures, known as autophagosomes. Besides, as an important host defense pathway, autophagy is also a target for tombusviruses to prevent its antiviral activities. In this study, I identify the role of key autophagy related genes, Atg11, Atg8, and Atg2, which are involved in autophagosome formation, and …

Erwinia Amylovora Phage Therapy: Biocontrol Formulation, Receptor Identification, Resistance Mechanisms, Nassereldin Ibrahim

Theses and Dissertations (Comprehensive)

Fire blight is known as a disease of Rosaceae and it displays infection symptoms in about 200 species in 40 rosaceous genera. The most economically important crops that are affected by fire blight are apples and pears. Fire blight can cause severe outbreaks and a single fire blight outbreak can disrupt orchard production for years. The bacterium that causes this disease is indigenous in North America, and according to Statistics Canada, economic losses in apples and pears were valued at an estimated $4 million in 2005, which is approximately 5% of the total production. In addition, production costs can increase …

Role Of Ph And Plant Age On The Selection Of Rhizobial Endophytes In Soybean Root Nodules, Cole Alexander Roman

Graduate Theses/Dissertations

Soybeans form symbiotic relationships with nitrogen-fixing bacteria in their root nodules to acquire most of their nitrogen requirement; nitrogen is often one of the limiting nutrients in the soil. Members of the Bradyrhizobium, Sinorhizobium, Mesorhizobium, and Rhizobium genera can nodulate soybeans. Bradyrhizobium is preferentially selected over other types of rhizobia in varying environmental conditions and is often found in acidic soils. Sinorhizobium is often identified in the root nodules of soybeans in neutral and alkaline soil. So far, the potential role of soil pH on the selection of rhizobial endophytes with soybean root nodules is unknown. Likewise, …

The Role Of The Vibrio Cholerae Type Vi Secretion System During Kin Cell Interaction, Biofilm Formation And Priority Effects, Karen A. Castro

Dissertations and Theses

Vibrio cholerae’s Type VI secretion system (T6SS) is one of the arsenals used by the bacteria for its long-term survival in different environments, against a variety of opponents, and for its maintained pathogenicity in vulnerable regions of the world. Therefore, the more we understand about the activity of the T6SS, the closer we get to understanding its role in bacterial competition; inter-and-intra, and how this shapes a bacterial niche. Further, although the probiotic-like effect in the V. cholerae vaccine is described to work fast due to niche uptake hindering colonization of toxigenic strains, it is not yet clear if there …

The Effect Of Nanoconfined Liquid Properties On The Water-Responsive Behavior Of Bacterial Cell Walls, Seungri Kim

Dissertations and Theses

Water-responsive (WR) materials have the ability to mechanically swell and shrink in response to changes in relative humidity (RH). These WR materials are used by many biological systems to perform essential tasks; for example, pinecones use WR materials to release their seeds in dry environments, and wheat awns open and close to propel seeds into the soil, driven by daily RH changes. The WR actuation of some biomaterials is extremely powerful, for example Bacillus subtilis cell walls display record-high actuation energy and power densities of 72 MJ m^-3 and 9.1 MW m^-3, surpassing those of all existing …

The Identification And Characterization Of Novel And Improved Antigens For Next-Generation Pertussis Vaccines, Gage Michael Pyles

Graduate Theses, Dissertations, and Problem Reports (ETD)

Whooping cough, or pertussis, is a highly infectious respiratory disease caused by infection with the Gram-negative bacterial pathogen Bordetella pertussis. Pertussis affects all age groups and populations; however, it is most severe in infants who are too young to receive vaccinations and remains a global health concern with more than­­­­ 200,000 cases reported globally in 2023. Vaccines against pertussis have been available in the United States since the 1940’s with the development and widespread use of whole cell pertussis vaccines. Following their introduction, the incidence of pertussis was controlled and limited to fewer than 5,000 cases per year. Despite …

Endogenous Glucocorticoid Signaling Is Required For Normal Macrophage Response To H. Pylori Infection, Stuti Khadka

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gastric cancer is the fifth leading cause of cancer-related deaths worldwide, affecting millions of people. H. pylori is the strongest risk factor for gastric cancer, with about 90% of the cases strongly associated with H. pylori infection. Half of the world's population is infected with this bacterium. However, only a small subset of the infected population (1-3 %) go on to develop gastric cancer. Diagnosis of the disease at an early stage is the biggest challenge because of the widespread prevalence of H. pylori infection and a long asymptomatic phase before the advanced stages. Patients are left with limited treatment …

Examining The Role Of Microbial Communities In Soil Carbon Cycling Across Levels Of Complexity, Chansotheary Dang

Graduate Theses, Dissertations, and Problem Reports (ETD)

Microorganisms provide the foundation for many ecosystem processes and are important drivers of carbon and nutrient cycling. The advancement of next generation sequencing has allowed researchers to lift open the lid on the ‘black box’ in microbial ecology. While previously unculturable microbes can now be characterized with the 16S rRNA gene, answering ‘who’s there?’ is only part of the challenge. Hidden inside the ‘black box’ remains the question, ‘who’s doing what?’. Recent development in trait-based methods like quantitative stable isotope probing (qSIP) equipped microbial ecologists with the tool to connect taxon-specific traits to ecosystem processes. Despite the growing body of …

Batch Culture Models Of The Murine Gut Microbiome & The Impact Of Simple Dormancy On Dormancy-Capable Microorganisms Models, Ana C. Mendez

Mathematics Dissertations - Archive

The proposed mathematical biology research utilizes mathematical models to gain insight into biological systems. These systems of ordinary differential equations model diverse topics, ranging from gut microbiomes to harmful algal blooms. A complete stability analysis, supporting phase plane portraits, bifurcation diagrams, and numerical simulations will accompany the models presented. In Chapter 2, the murine gut microbiome is modeled to match laboratory experiments in the literature. In these experiments, mice eat plasmid-carrying “donor” bacteria and naturally carry plasmid-free “resident” bacteria in their gut. The models aim to capture the behavior of plasmids, donor bacteria, and resident bacteria. Chapter 3 explores dormancy …

Inflammation And Tumor Progression: The Differential Impact Of Saa In Breast Cancer Models, Daniel Wilhelm Olivier, Carla Eksteen, Manisha Du Plessis, Louis De Jager, Lize Engelbrecht, Nathaniel Wade Mcgregor, Preetha Shridas, Frederick C. De Beer, Willem J. S. De Villiers, Etheresia Pretorius, Anna-Mart Engelbrecht

Saha Cardiovascular Research Center Faculty Publications

Background: Previous research has shown that the Serum Amyloid A (SAA) protein family is intricately involved in inflammatory signaling and various disease pathologies. We have previously demonstrated that SAA is associated with increased colitis disease severity and the promotion of tumorigenesis. However, the specific role of SAA proteins in breast cancer pathology remains unclear. Therefore, we investigated the role of systemic SAA1 and SAA2 (SAA1/2) in a triple-negative breast cancer mouse model.

Methods: Syngeneic breast tumors were established in wild-type mice, and mice lacking the SAA1/2 (SAADKO). Subsequently, tumor volume was monitored, species survival determined, the inflammatory profiles of mice …

Poor Water Quality As A Trigger Of Harmful Algal Blooms In Lake Manzala, Mohammed A. Hussein, Alaa Eldin Eissa, Reham M. Eltarabily, Mohamed F. Abdelghany, Mahmoud A. Elnakeeb, Eman M. Ismail, Reham H. Ragab, Amina A. Dessouki

Mansoura Veterinary Medical Journal

Objective: The current study aimed to assess the direct effects of poor water quality on the eruption of heavy harmful algal blooms and to assess the physicochemical properties of water in Lake Manzala, as well as the molecular identification of the retrieved green algae.

Procedures: Subsurface water samples were collected from three different sites in September 2023 for water quality assessment. Moreover, morphological and molecular identification of suspected harmful algae is the most reliable diagnostic tool for this eruption.

Results: This study was conducted in the northern and northeastern regions of Lake Manzala. These regions receive large amounts of municipal, …

Bloom: A Microbial Self-Portrait, Emily Lauren Mulvaney

Graduate Student Theses, Dissertations, & Professional Papers

No abstract provided.

Tetrodotoxin, Fungal Pathogen Infection, And Bacterial Microbiome Associations Are Variable In The Skin Microecosystems Of Two Taricha Newt Species, Talon B. Jost

EWU Masters Thesis Collection

Chytridiomycosis is an amphibian disease linked to population declines and species extinctions, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). While chytridiomycosis can result in host death, some amphibians are less susceptible to severe infections through intrinsic factors including host-associated skin microbes aiding defense through resource competition and antifungal metabolite production. Amphibians can also release toxins in response to stress cues to defend against disease, parasitism, and predation. Tetrodotoxin (TTX) is a potent low molecular weight neurotoxin found in genus Taricha, and despite a previously observed negative relationship between differential levels of TTX concentration and Bd infection presence within a …

Synthetic Microbial Communities For Plastic Upcycling, Isabel B. A. Valencia

Dissertations, Master's Theses and Master's Reports

Plastic waste and human hunger pose major threats to the health and wellbeing of populations world-wide. Using microbial methods to upcycle polyethylene terephthalate (PET) plastic into value-added compounds such as single cell protein (SCP) for human consumption is a unique solution to both these issues. Two monomers of chemically deconstructed PET (DCPET), terephthalate (TPA) and ethylene glycol (EG), have been previously shown to be biodegradable by enriched microbial communities. Using this top-down knowledge to inform the reconstruction of a minimal microbial community constructed from isolated members of these communities is a novel way to efficiently process these monomers via a …

Optimization Of An Immune Assay To Detect Binding Of Nod2 To Staphylococcus Aureus, Precious Mckenzie

All Student Theses and Dissertations

Staphylococcus aureus, a gram-positive, commensal bacterium, is the cause of a multitude of opportunistic diseases and infections. While S. aureus has evolved ways to escape innate immune responses in the host, the mechanisms are not fully understood. One area of active research involves mechanisms by which S. aureus avoids detection by Pattern Recognition Receptors (PRRs), such as Nuclear Oligomerization Domain 2 (NOD2), present on the surface of and inside innate immune cells. This study aimed to design and optimize an assay that can be utilized to investigate S. aureus components that contribute to the activation of NOD2 receptors. The …

Optimization Of Buffers Used In Phycobiliprotein Extraction From The Cyanobacterium Acaryochloris Marina, Rinah Fleisher

Williams Honors College, Honors Research Projects

Optimization of buffers used in phycocyanin extraction from A. marina was explored including acetate, phosphate, and citrate buffers as well as deionized water as a negative control. Samples were extracted in triplicates for each trial with two extraction trials completed overall for citrate buffer (n=6), phosphate buffer (n=6), acetate buffer (n=6), and deionized water (n=6). Results reflect no statistical difference in phycocyanin content (μg/mL) between each buffer or deionized water control. Though no statistically significant differences between treatment groups were found, phosphate buffer yielded the greatest phycocyanin content and the deionized water negative control yielded the lowest phycocyanin content overall. …

Determination Of Spore Viability In Concrete Across Several Factors Using Most Probable Number, Samuel Boyer

Williams Honors College, Honors Research Projects

To determine the lowest concentration of spore added to polyurethane-cement composite (PUCCO) particles that can still germinate after curing in concrete. This research project is a small addition to the larger research project being undertaken by Mirza Mohammed Rashiduzzaman for his Masters. The larger project involves the use of fungal spores added in concrete to act as a self-healing component when cracks form in the concrete structure over time. These spores are suspended in a protective oil and loaded into small, hardened sponge-like PUCCO cubes to act as growth points when water and air can reach the PUCCO in the …