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Bacterial Diversity And Function Within An Epigenic Cave System And Implications For Other Limestone Cave Systems, Kathleen Merritt Brannen-Donnelly

Doctoral Dissertations

There are approximately 48,000 known cave systems in the United States of America, with caves formed in carbonate karst terrains being the most common. Epigenic systems develop from the downward flow of meteoric water through carbonate bedrock and the solutional enlargement of interconnected subsurface conduits. Despite carbonate karst aquifers being globally extensive and important drinking water sources, microbial diversity and function are poorly understood compared to other Earth environments. After several decades of research, studies have shown that microorganisms in caves affect water quality, rates of carbonate dissolution and precipitation, and ecosystem nutrition through organic matter cycling. However, limited prior …

Scardovia Wiggsiae Prevalence In Orthodontic Patients, Brandon Joseph Streiff

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dental caries has mainly been associated with Streptococcus, Lactobacillus, Actinomyces and Veillonella species. But in recent salivary studies a new cariogenic pathogen, has been identified. This new bacteria, Scardovia wiggsiae (SW), is currently being tested within the UNLV School of Dental Medicine patient population. Although these current studies are being conducted to study its prevalence in both pediatric and adult populations, it has not been evaluated among patients with an altered oral environment as seen in patients with orthodontic appliances. Fixed orthodontic appliances increase the difficulty of removing daily plaque on and in between the teeth with standard oral hygiene …

Rare Occurrences Of Free-Living Bacteria Belonging To Sedimenticola From Subtidal Seagrass Beds Associated With The Lucinid Clam, Stewartia Floridana, Aaron M. Goemann

Masters Theses

Lucinid clams and their sulfur-oxidizing endosymbionts comprise two compartments of a three-stage, biogeochemical relationship among the clams, seagrasses, and microbial communities in marine sediments. A population of the lucinid clam, Stewartia floridana, was sampled from a subtidal seagrass bed at Bokeelia Island Seaport in Florida to test the hypotheses: (1) S. floridana, like other lucinids, are more abundant in seagrass beds than bare sediments; (2) S. floridana gill microbiomes are dominated by one bacterial operational taxonomic unit (OTU) at a sequence similarity threshold level of 97% (a common cutoff for species level taxonomy) from 16S rRNA genes; …

Image-Charge Detection €“ Novel Instrumentation And Applications, Brandon Lee Barney

Theses and Dissertations

Image-charge detection is an analytical technique in which a highly-charged particle is detected by the magnitude of the image current that it generates in a detecting electrode. This current is represented as a voltage between the charged particle and the sensing electrode. It is a single particle detection method, ideal for the analysis of large, variable mass particles such as biological cells. Some of the physical properties of Bacillus subtilis spores were explored using different applications of image-charge detection. B. subtilis is a gram-negative spore-forming bacteria that has been shown to exhibit extremophile behavior. The particular extremophile behavior that was …

Engineering Novel Detection And Treatment Strategies For Bacterial Therapy Of Cancer, Jan T. Panteli

Doctoral Dissertations

Finding and treating cancer is difficult due to limited sensitivity and specificity of current detection and treatment strategies. Many chemotherapeutic drugs are small molecules that are limited by diffusion, making it difficult to reach cancer sites requiring high doses that lead to systemic toxicity and off-target effects. Tomographic detection techniques, like PET, MRI and CT, are good at identifying macroscopic lesions in the body but are limited in their ability to detect microscopic lesions. Biomarker detection strategies are extremely sensitive and able to identify ng/ml concentrations of protein, but are poor at discriminating between healthy and disease state levels due …

High Salinity Stabilizes Bacterial Community Composition And Activity Through Time, Tylan Wayne Magnusson

Theses and Dissertations

Dormancy is a plausible strategy for bacteria to overcome the effects of temporal fluctuations in resources or stresses and await more “optimal” conditions to resume metabolic activity and growth. Seasonal changes in environmental conditions force microbes to adjust their metabolic activity accordingly, and community composition drastically shifts. In extreme environments, however, the overriding effects of a constant stress may constrain the need or benefit of bacteria entering dormancy. In hypersaline lakes, high metabolic activity is required to maintain adaptations that permit survival. Sampling from six lakes on a salinity gradient (0.05% – 30.3%), we measured seasonal fluctuations in bacterial dormancy …

Dna Analysis Of Surfactant Associated Bacteria In The Sea Surface Microlayer In Application To Satellite Remote Sensing Techniques: Case Studies In The Straits Of Florida And The Gulf Of Mexico, Bryan Hamilton

HCNSO Student Theses and Dissertations

Several genera of bacteria residing in the sea surface microlayer and in the near-surface layer of the ocean have been found to be involved in the production and decay of surfactants. Under low wind speed conditions, surfactants can suppress short gravity capillary waves at the sea surface and form natural sea slicks. These features can be observed with both airborne and satellite-based synthetic aperture radar (SAR). Using a new microlayer sampling method, a series of experiments have been conducted in the Straits of Florida and the Gulf of Mexico in 2013 to establish a connection between the presence of surfactant-associated …

Comparative Analysis Of Anti-Bd Bacteria From Six Malagasy Frog Species Of Ranomafana National Park, Kelsey Savage

Senior Honors Projects, 2010-2019

As Malagasy amphibians are facing an impending extinction crisis from the lethal skin fungus Batrachochytrium dendrobatidis (Bd), it has become imperative to proactively mitigate the threat. Bd sporangia develop in the skin of infected amphibians and cause the skin to thicken, leading to ionic imbalance and eventual heart failure. It has been shown that certain bacterial species are able to inhibit Bd growth on amphibians by producing antifungal metabolites. Community-based probiotics are one approach used to combat chytridomycosis by inoculating an environment with Bd-inhibitory bacteria so that many amphibian species are treated at once. With this method, it is important …

Identification Of Bacterial Species Using Colony Pcr, Kaiti Walker

Honors Theses

My research consisted of two separate parts, both involving the PCR methods. In part one I was trying to identify bacteria isolated from a chicken coop. In part two I was trying to identify bacteria isolated from the bluff. In both parts, I used a technique called colony PCR. This concept uses a single colony of bacteria to complete the PCR reaction. One pipet tip from a single colony is selected from the plate and mixed into a tube containing ultrapure water. A small amount of this bacterial mixture is then added into the PCR reaction. In the first part …

Potential For Biocontrol Of Environmental Vibrio Spp. By Predatory Bacteria Bacteriovorax, Patrick Tennis

OES Theses and Dissertations

The scale of predator-prey interactions varies from the iconic (e.g., lions and gazelles) to the microscopic (e.g., protists and bacteria). Bdellovibrio-and-like-organisms (BALOs) are bacteria that prey upon other Gram-negative bacteria, including pathogens. In particular, the halophilic genus Vibrio, many species of which are disease agents, has been shown to be susceptible to attack by BALOs. One motivation of the present research is to assess the potential for biocontrol of Vibrio by Bacteriovorax. This investigation is the first to test the susceptibility of Vibrio strains (n = 26) originating from a variety of geographic locations to predation by …

Characterization Of Two Biochars Derived From Horse Muck And Their Ability To Reduce Pathogen Transport In Soil, David Griffith

Theses and Dissertations--Biosystems and Agricultural Engineering

Biochars have been created and characterized from a variety livestock manure biomass including poultry, dairy, and swine. However, no research has been conducted on the physical and chemical makeup of biochar pyrolyzed from horse muck. Two horse muck derived biochars containing either straw (HS) or woodchip (HW) bedding were pyrolyzed at 700°C and characterized for their physical and chemical properties. Tests revealed both biochars had high alkalinity, moderate specific conductivity, and low surface area as compared to other biochars in the literature. HS contained more mineral structures than HW. Scanning electron microscopy presented differences in particle shape, size, and presence …

Anthropogenic Litter And Microplastic In Urban Streams: Abundance, Source, And Fate, Amanda Rae Mccormick

Master's Theses

The accumulation and ecological effects of anthropogenic litter (AL) and microplastic are well-documented in marine ecosystems, but these materials’ abundances in rivers is unknown. AL enters rivers from recreation, runoff, and illegal dumping. Microplastic fibers and pellets are abundant in wastewater treatment plant (WWTP) effluent which enters rivers. Our objectives were to: (1) quantify AL abundance and composition in urban streams, (2) measure AL flux, accumulation, and export, and (3) measure riverine microplastic concentration and analyze its bacterial communities. We collected AL from 5 urban streams and observed greater AL density in riparian habitats and greater mass in benthic habitats. …

Integrated Nanoscale Imaging And Spatial Recognition Of Biomolecules On Surfaces, Congzhou Wang

Theses and Dissertations

Biomolecules on cell surfaces play critical roles in diverse biological and physiological processes. However, conventional bulk scale techniques are unable to clarify the density and distribution of specific biomolecules in situ on single, living cell surfaces at the micro or nanoscale. In this work, a single cell analysis technique based on Atomic Force Microscopy (AFM) is developed to spatially identify biomolecules and characterize nanomechanical properties on single cell surfaces. The unique advantage of these AFM-based techniques lies in the ability to operate in situ (in a non-destructive fashion) and in real time, under physiological conditions or controlled micro-environments.

First, AFM-based …

Characterization Of The Interaction Between Ftsz-Ring Stabilizer Zapc And The Conserved Protease Clpxp In E. Coli Cytokinesis, Andrea Cardenas Arevalo

Dissertations and Theses

Cell division in bacteria requires the assembly of a macromolecular protein machinery at midcell that is spatiotemporally regulated during the bacterial cell cycle. Central to the process of division is the assembly of a cytokinetic ring-like structure, termed the Z-ring, formed by polymers of the essential tubulin-homolog FtsZ. Polymerization of FtsZ is regulated by a number of proteins that bind FtsZ and regulate its assembly/disassembly mechanisms. Despite being extensively studied, the molecular nature of the diverse protein-protein interactions that regulate the assembly of FtsZ during early stages of division is not well understood. Here, I focus on an FtsZ-ring stabilizer …

Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms

Theses and Dissertations (Comprehensive)

Biofilms are a growing concern in the medical field due to their increased resistance to antibiotics. When found in a biofilm, bacteria can have antibiotic resistance 10-1000 times that of their planktonic counterparts. Therefore, it is important to study the formation of biofilms. Cellulose biofilms are formed by Enterobacteriaceae, such as many Escherichia coli and Salmonella spp. strains. Biofilms provide these species with benefits including antimicrobial protection, development of bacterial communities, promotion of DNA exchange, uptake of nutrients, and, in the case of cellulose biofilms, immune system evasion. Cellulose biofilms are controlled by the Bacterial cellulose synthesis (Bcs) complex located …

Impact Of Biofilm Formation And Composition On Antibiotic Resistance In Environmental Isolates Of Escherichia Coli And Salmonella Spp., Raluca Tutulan

Theses and Dissertations (Comprehensive)

Escherichia coli and Salmonella spp., like most bacteria, prefer to grow in biofilms. These biofilms provide bacteria with protection from harsh environmental factors (such as desiccation and changes in pH), aid in the evasion of host immune responses and provide increased antibiotic resistance. Biofilms are present in non-host environments (e.g. water pipes) as well as in mammalian hosts (in the healthy gastrointestinal microbiota and in over 65% of nosocomial infections). Two important components utilized by E. coli and Salmonella spp. to form biofilms are cellulose and curli fimbriae. Curli fimbriae mediate the attachment of bacteria to abiotic surfaces and …

A Comparative Analysis Of The Moose Rumen Microbiota And The Pursuit Of Improving Fibrolytic Systems., Suzanne Ishaq Pellegrini

Graduate College Dissertations and Theses

The goal of the work presented herein was to further our understanding of the rumen microbiota and microbiome of wild moose, and to use that understanding to improve other processes. The moose has adapted to eating a diet of woody browse, which is very high in fiber, but low in digestibility due to the complexity of the plant polysaccharides, and the presence of tannins, lignin, and other plant-secondary compounds. Therefore, it was hypothesized that the moose would host novel microorganisms that would be capable of a wide variety of enzymatic functions, such as improved fiber breakdown, metabolism of digestibility-reducing or …