Microbiology Commons^™

"Dental Health For Mental Wealth": A Comprehensive Analysis Of The Underexplored Impact Of Oral Health And Behaviors On Neurobiology And Psychological Well-Being, Brooke C. Beck

Mahurin Honors College Capstone Experience/Thesis Projects

This thesis explores the link between oral health and psychological state, specifically, the effect of oral health on psychological state and how appropriate oral health impacts this relationship. A review of the literature was conducted and studies interpreted within the scope of oral health’s impact on psychological health and detailing some of the pathways proposed for such a link. The literature search was limited to the English language from well-known databases mainly from 2015 to 2025. A few outliers are present to include foundational information.

The effects of oral disease and oral self-care behaviors were dissected through a biochemical perspective, …

Propelling Whole-Cell Biosensor Creation By Leveraging Gene Fusion To Assemble Synthetic Functional Transcription Factors For The Detection Of Biomarkers, Samuel J. Verzino

Theses and Dissertations

Biosensors are analytical devices that leverage biological modules for the detection of molecules of interest. As customizable tools designed to aid in a wide array of diagnostics, these instruments are rapidly advancing the field of synthetic biology. While varied in their construction and purpose, biosensors are ultimately concerned with converting a physicochemical stimulus into a detectable signal. Among the many existing variants, whole-cell biosensors (WCBs) stand out due to their versatility and engineering potential. WCBs are a type of biosensor in which a physiologically active cell sustains an array of biomolecular elements - receptors, transporters, regulators, etc. - capable of …

Full Issue, Catalina Cuellar-Gempeler

Humboldt Journal of Microbiology

No abstract provided.

Antimicrobial-Resistant Enterococcus In Urban Communities: Insights Into Human Infection Risks, Sumit Kumar Paudel

Wayne State University Dissertations

The complexity of community risk factors and transmission routes has been a major challenge to the containment of community-acquired antibiotic resistance. Possible factors range from environmental contamination, antibiotic misuse, and human exposure via animals, food, the environment, and human-to-human transmission. What has been missing from previous research is the integration of findings in animal and environmental sectors with bacteria implicated in community infections. To gain a better understanding of antibiotic resistance acquired in the community, a one health approach is clearly needed. Specifically, we aim to investigate the prevalence of antibiotic-resistant Enterococcus in wildlife, their gene profiles in comparison with …

René Dubos: An Annotated Bibliography, Carol L. Moberg

René Dubos: An Annotated Bibliography

René Dubos (1901–1982), a prominent 20th century scientist, humanist, and philosopher, was a prolific author. Affiliated for more than 50 years with The Rockefeller Institute for Medical Research/The Rockefeller University, his studies ranged from antibiotics and the role of bacteria in human diseases to formulating broad ecological and environmental questions affecting human health and disease. His seminal writings explore a lifelong belief that a living organism—whether microbe, human being, society, or the Earth itself—could be understood only through its relationships with everything else.

This comprehensive bibliography of more than a thousand works by René Dubos includes brief annotations for each …

Impact Of Glufosinate On Soil Microbial Community Dynamics, Sarobi Das

Biology Dissertations - Archive

The increasing global regulations of glyphosate due to its possible carcinogenicity and environmental hazards have necessitated the search for alternative herbicides. Glufosinate-ammonium offers a sustainable attribute due to its low toxicity and limited reported herbicide resistance cases. Despite its increasing agricultural importance, very limited studies are done on its environmental impact, especially on the soil systems. This thesis examines the ecological behavior of glufosinate in soil, precisely focusing on its effect on the dynamics of soil microbiome and the potential use of Bradyrhizobium japonicum USDA110 for bioremediation by reversing the effect of microbial dysbiosis. A series of 30-day mesocosm studies …

Clonal Variation In Effector Gene Expression As A Mechanism For Pathogenic Adaptation In Magnaporthe Oryzae, Rebekah J. Ellsworth

Theses and Dissertations--Plant Pathology

Magnaporthe oryzae is a filamentous fungal pathogen that causes destructive diseases in cereals, including rice blast, wheat blast, and gray leaf spot. It is responsible for 10–30% annual yield losses in rice (Nalley et al., 2016) and up to 100% loss in wheat under favorable conditions (Kohli et al., 2011). Disease management typically relies on the use of resistant cultivars, but M. oryzae rapidly overcomes host resistance by mutating or deleting avirulence (AVR) genes recognized by host immune receptors. This rapid adaptation, often occurring within one to two growing seasons, presents a major challenge to breeding for durable resistance.

The …

Schistosoma Mansoni Infection Causes Consistent Changes To The Fecal Bacterial Microbiota Of Mice Across And Within Sites, Mariam A. Mhanna, David T. Gauthier, Lisa M. Shollenberger

Biological Sciences Faculty Publications

Eggs of Schistosoma mansoni are produced by adult female worms in mesenteries of infected hosts. Eggs can cross the intestinal barrier and form granulomas in the tissue or breach and exit the host through fecal excretion. These interactions may affect the host microbiome assemblages. Given the potential for schistosomal alteration of host gut microbiome and subsequent effects on the fecal bacterial composition, it is important to conduct controlled microbiome studies on model animals. While pursuing these studies, it is important to take into account the different conditions in which microbiome studies are conducted and their consequent impacts on variability and …

Genetic Analysis Of Methionine Restriction-Associated Mitochondrial Unfolded Protein Response Signaling., Josh D. Dodge

Biology Dissertations - Archive

The lifespan of an organism is dictated by various genetic and environmental factors. One such determinant is the health of mitochondria which are organelles that mediate various critical cell functions including a significant role in generating the vast supply of cellular energy. Indeed, the gradual decline of mitochondrial function is believed to be a hallmark and possible cause of aging. Paradoxically, mild mitochondrial dysfunction early in life extends lifespan in various model organisms. Cells use diverse approaches to promote mitochondrial homeostasis, including the transcriptional reprogramming of cells by mitochondrial unfolded protein response (UPRmt) to mitigate mitochondrial stress. Consistently, UPRmt activation …

For Dust Thou Art, And Unto Dust Shalt Thou Return — Testing Soil-Derived Plant-Beneficial Bacteria For Potential As Biofertilizers, Johnathon Brim, Blake Oler, Jacob Hardy, Joseph Richardson, Ryan Bjazevich, Kate Whalen, Emmelia Wevers, Foxx Naylor, Ethan Shreeve, Alex Cherry, Ethan Cherry, Tanner Gunnell, Jayden Longhurst, Andrew Burrows, Mailon Odell, Jacob Sy, Jeffrey Schacterle

Library/Life Sciences Undergraduate Poster Competition 2025

• The results of plant testing have shown that bacteria treated seeds outperform the control seeds on a consistent basis
• We will continue to receive more data from out own experiments as well as crowdsourcing methods.
• Our next step is to begin comparing results of our soil/seed treatment against commercially available fertilizers that use beneficial bacteria.

Effects Of Climate Change On Fungal Diversity And Function In Streams, Syeda Tasfia Imam

Masters Theses

"This study investigated the impact of climate change, particularly drought, on leaf decomposition and associated fungal and macroinvertebrate communities in freshwater ecosystems. With climate change, streams may experience altered hydrology, leading to shifts in community composition and biogeochemical processes. Fungi decompose organic matter, facilitate nutrient cycling, and support food webs. However, drought can disrupt these processes by reducing water availability, causing declines in fungal diversity and activity. I examined leaf breakdown and associated biota in 13 stream sites across varying hydrologic conditions, from perennial to ephemeral flow patterns. Flow duration varied during the 8-week study. Leaf breakdown was significantly related …

Isolation And Characterization Of A Halophilic, Extremely Acidophilic, Iron-Oxidizing Bacterium, Connor Crites

Masters Theses

This thesis describes the isolation and characterization of a halophilic iron- oxidizing bacterium from sediments obtained from Lake Magic; an extremely acidic, saline lake located in Western Australia. The purpose for the isolation of novel, halotolerant/halophilic iron-oxidizing bacteria is to aid in metal-mining bioleaching operations. Currently used iron- and sulfur-oxidizing bacteria are extremely sensitive to chloride, which restricts their use in these industries.

A singular bacterial morphology was isolated from Lake Magic sediments that was roundly-rod shaped, 1-2 um in length, and stained Gram-negative. This organism was able to grow in a modified medium (DSM14174) using ferrous sulfate as an …

Unveiling The Bacterial Communities Of Aphaenogaster: Taxonomic Composition, Developmental And Species Influences, And The Impact Of Climate Change, Lily Kelleher

West Chester University Master’s Theses

Ants are vital keystone species in many ecosystems because they provide ecosystem services such as: seed dispersal, soil bioturbation, and pest control. However, ant bacterial symbioses remain largely unstudied, but these interactions are crucial because microbes play a vital role in the ants’ overall health. Today, global climate change is impacting our biodiversity, and we can use information about how changing temperatures impact the symbiotic bacterial communities associated with ants to predict future impact. Aphaenogaster rudis and A. fulva remain understudied in terms of their bacterial community and are important North American species. For this study, ants from several colonies …

The Antibiofilm Efficacy Of Copper And Zinc-Enhanced Borate Bioactive Glasses On Polymicrobial Biofilms, Sarah Fakher, David J. Westenberg

Biological Sciences Faculty Research & Creative Works

Healthcare-acquired infections (HAIs) are a significant global challenge driven by biofilm-forming pathogens. Polymicrobial biofilms, involving interactions between multiple microbial species, exacerbate treatment difficulties due to their enhanced resistance to antimicrobial therapies. Borate bioactive glasses (BBGs) are an emerging class of biomaterials that have attracted significant interest in infection control. The incorporation of copper and zinc into the BBG matrix can effectively disrupt biofilm formation and bacterial colonization. This study investigates the antibiofilm efficacy of copper and zinc-doped BBGs against polymicrobial biofilms formed by S. epidermidis, E. coli, and P. aeruginosa. Using static and dynamic biofilm models, BBGs were applied through …

Cath-Ddg: Towards Robust Mutation Effect Prediction On Protein-Protein Interactions Out Of Cath Homologous Superfamily, Guanglei Yu, Xuehua Bi, Teng Ma, Yaohang Li, Jianxin Wang

Computer Science Faculty Publications

Motivation: Protein-protein interactions (PPIs) are fundamental aspects in understanding biological processes. Accurately predicting the effects of mutations on PPIs remains a critical requirement for drug design and disease mechanistic studies. Recently, deep learning models using protein 3D structures have become predominant for predicting mutation effects. However, significant challenges remain in practical applications, in part due to the considerable disparity in generalization capabilities between easy and hard mutations. Specifically, a hard mutation is defined as one with its maximum TM-score < 0.6 when compared to the training set. Additionally, compared to physics-based approaches, deep learning models may overestimate performance due to potential data leakage.

Results: We propose new training/test splits that mitigate data leakage according to the CATH homologous superfamily. Under the constraints of physical …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

Assessing The Role Of Daily Thermal Fluctuations In The Performance Of Mitochondrial Energy Transduction Of The Centrarchid, Lepomis Cyanellus, Grayson Hofmann

Masters Theses

Freshwater systems are affected by current climate extremes, forcing species found in these systems to withstand drastic changes in temperature. Temperature changes affect these organisms by altering their metabolic rate and energy balance. Increases in temperature can lead to an increase in oxygen consumption, which ultimately increases the need for more energy production. Mitochondrial energy transduction of green sunfish (Lepomis cyanellus) and many other fish species after a thermal insult, has hardly been explored. This study complements the limited research available on mitochondrial function in similar species, as they ignore the possibility of consecutive thermal events, which are …

Ribomoe: An Application Of Mixture Of Experts On Artificial Riboswitch Classification, Hainian Audrey Long

Master's Projects

Urban water sewage is a potential health concern due to its possibility to spread contagious RNA viruses such as Coxsackievirus B3. However, detection of viral particles remains challenging because of low viral concentrations in wastewater and high mutation rates of the RNA virus. To address this, this study proposes a novel viral detection method using synthetic riboswitches that bind to the target virus and trigger a reporter gene, amplifying the detection signals. To support the design of effective riboswitches, we present a machine learning model for classifying riboswitch performance, integrating RNA sequence data with secondary structural features. This model used …

Isolation, Characterization & Identification Of Cultivable Field Pea Seed Bacteria In South Dakota, Diana Wairimu Njuguna

Electronic Theses and Dissertations

Pea (Pisum sativum L.) is a legume, cultivated on over 25 million acres, particularly in Canada, France, China, Russia, and the United States. Its seeds harbor microbiota including bacteria and fungi, either on the surface (epiphytes) or within seed tissues (endophytes). These microbes can be pathogenic or beneficial, enhancing seedling metabolism and protection from environmental stresses. Characterizing beneficial seed microbiota enables development of microbial inoculants for seed treatment. Seeds from 12 varieties (green or yellow seed coats) were harvested from Sturgis and Dakota Lakes in 2021. Epiphytes were extracted using sonication followed by grinding the seeds to obtain endophytes. Isolates …

The Formation And Degradation Of Carboxysomes During Heterocyst Development In Filamentous Cyanobacteria, Maxwell Anton Jakubiak

Electronic Theses and Dissertations

Photosynthetic carbon (CO2) fixation and solar-powered nitrogen (N2) fixation are foundational biochemical processes that introduce essential elements into the biosphere. While atmospheric dinitrogen gas (N2) is unusable to most organisms, diazotrophs utilize the nitrogenase enzyme to reduce N2 to ammonia. Because all known nitrogenases are highly susceptible to irreversible oxygen inactivation, N2 fixation is generally incompatible with oxygenic photosynthesis. However, several cyanobacteria are both photosynthetic and diazotrophic, balancing these opposing metabolisms by temporally or spatially separating the respective enzymes. Anabaena sp. PCC 7120 is a model multicellular cyanobacterium that grows in filaments of photosynthetic vegetative cells, which respond to nitrogen …