Other Microbiology Commons^™

The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette

Master's Theses

The elasmobranch osmoregulatory strategy is predicated on the accumulation of nitrogenous compounds, primarily urea and trimethylamine n¬-oxide (TMAO). Despite the abundance of these plasma osmolytes, it is notable that elasmobranchs appear to lack urease and TMA oxidase (Tmase), enzymes that scavenge urea-nitrogen and synthesize TMAO, respectively. However, urease and Tmase are found in many species of bacteria. Therefore, I hypothesized that intestinal bacteria are responsible for urease and Tmase activity in elasmobranchs. Absent dietary nitrogen sources, I evaluated the effects of reduced intestinal microbiota on osmoregulation in Atlantic stingray (Dasyatis sabina) in vivo. D. sabina were given …

Fecal Bacterial Communities As An Indicator Of Trophic Interactions Among Anuran Larvae, Steven Jacob Everman

Master's Theses

Anurans are mass spawners, often with multiple females spawning together, resulting in thousands of tadpoles sharing a habitat. Such large numbers of tadpoles with limited dispersal can lead to intense competition for resources. Inter and intra-specific competition for food could have negative impacts on the growth and survival of smaller tadpoles. Fecal bacterial communities have the potential to be used as indicators of changes in diet making it possible to determine if tadpoles in the wild are eating the same food or not. After feeding on two prepared diets that differed in the percentage of complex carbohydrates, the fecal bacterial …

Identification Of Microorganisms Isolated From Mars-Bound Spacecraft Using Maldi-Tof, Melanie K. Phillips

STAR Program Research Presentations

The primary goal of the Biotechnology and Planetary Protection Group (BPPG) at the Jet Propulsion Laboratory (JPL) is to prevent microbial contamination between Earth and other planetary bodies. This helps preserve the ability to study other worlds as they exist in their natural states and protects our biosphere from extraterrestrial life. The process for identifying microbes located on space-bound hardware in JPL can be more efficient and precise by using the technique called matrix-assisted laser desorption and ionization time of flight (MALDI-TOF). Once this identification technique is fully implemented, the process time will be reduced from two weeks to one …

Identification, Characterization, And Life Cycle Of Intein-Associated Homing Endonucleases, Joshua J. Skydel

Honors Scholar Theses

Inteins are molecular parasites that have been identified in unicellular organisms from the three domains of life. The intein self-excises following translation of the host gene, and therefore incurs a fitness cost for its carrier. The symbiotic state of the intein to its host is dependent on the presence or absence of a homing endonuclease domain, which facilitates horizontal transfer of the molecule. Identification of this domain provides information on the evolutionary history of the intein, as well as patterns of horizontal gene transfer in microbial communities. I have therefore developed Hidden Markov Models (HMMs) to identify homing endonuclease domains …

Engineering A Mutation In The Heparin Binding Pocket Of The Human Fibroblast Growth Factor, Roshni Patel

Chemistry & Biochemistry Undergraduate Honors Theses

Fibroblast growth factors (FGFs) are family of proteins that belong to a group of growth factors that are found in mammals and play an important role in angiogenesis, differentiation, organogenesis, and tissue repair. In summary, their main functionality is involved in cell division and proliferation. Because FGFs plays such a vital role in cell proliferation, they are mainly involved in the process of wound healing and injuries. FGF binds to its ligand, heparin—a heavily sulfated glycosaminoglycan. The binding of heparin to FGF occurs through electrostatic interactions, specifically between the negatively charged sulfate groups on heparin and positively charged residues such …

Oxidative Stress Response In Archaea: Elucidation Of Oxidant Sensing And Tolerance Mechanisms In Methanosarcina Acetivorans, Matthew Edward Jennings

Graduate Theses and Dissertations

Methanogens are archaea possessing a conserved metabolic pathway which produces methane. Many of the enzymes in the methanogenesis pathway are Fe-S proteins, meaning methanogens are sensitive to conditions which disrupt Fe-S clusters. Molecular oxygen is capable of disrupting Fe-S clusters through oxidation of the iron atoms. Furthermore, reduced iron can facilitate the production of reactive oxygen species (ROS), meaning methanogens must possess antioxidant mechanisms. Detection and eradication of ROS is important for all cells, due to the potentially fatal consequences of unchecked oxidation. This dissertation presents two separate projects investigating mechanisms the model methanogen Methanosarcina acetivorans possess for dealing with …

Effects Of Lactobacillus Rhamnosus Milk Isolate On The Production Of Inflammatory Cytokines In Enterocytes, Beverly C. Ngeny

Electronic Theses and Dissertations

In the gastrointestinal tract, probiotics have been shown to promote host immunity and to regulate immune signaling pathways. This study used Caco-2 cell line to examine the effects of a Lactobacillus rhamnosus isolate from “amabere amaruranu” a Kenyan traditional cultured milk, on the production inflammatory cytokines in enterocytes. Live Lactobacillus rhamnosus (MRS6AN), its cytoplasmic fraction (CF), filtered spent broth (FSB) or heat inactivated FSB (HIB) were used as treatments on differentiated Caco-2 cell monolayer in transwells. Cytokine content in the cell lysates, apical and basolateral supernatants were determined using ELISA. Caco-2 cell lysate treatments showed significantly increased anti-inflammatory TGF-β (ng/ml) …

The Prevalence Of Escherichia Coli And Fecal Coliforms On Backpacks Of College Students In Central Kentucky, Samantha Mcmichael

Butler Journal of Undergraduate Research

Abstract

Escherichia coli (E. coli) is a gram negative, rod-shaped, facultative anaerobic bacterium, it is normally found in the lower intestines of warm-blooded animals and humans. E. coli and/or fecal coliforms have been used as fecal indicators in water, food, and contact surfaces. The purpose of this experiment is to identify the prevalence of E. coli and fecal coliforms on the bottom of backpacks belonging to college students in central Kentucky. Forty samples were taken from bottoms of college students’ backpacks in central Kentucky. Sterile swabs were used to collect the samples from the backpacks. The swabs …

Aeromonas Hydrophila In Amphibians: Harmless Bystander Or Opportunistic Pathogen, Zachary P. Rivas

Honors Undergraduate Theses

For several decades amphibian populations have been declining. Historically, the bacterium A. hydrophila (Ah) was hypothesized to be the causal factor in amphibian disease and population declines. However, with the discovery of a chytrid fungus, Batrachochytrium dendrobatidis (Bd) in 1998, which was identified on the skin of amphibians during documented mortality events, Ah research became of minor interest as focus shifted to Bd. Recent studies into the immunocompromising abilities of Bd, however, have opened new questions about its relationship with Ah and their combined effects on a host.

In this study, I explore the …

Interactomics-Based Functional Analysis: Using Interaction Conservation To Probe Bacterial Protein Functions, J. Harry Caufield

Theses and Dissertations

The emergence of genomics as a discrete field of biology has changed humanity’s understanding of our relationship with bacteria. Sequencing the genome of each newly-discovered bacterial species can reveal novel gene sequences, though the genome may contain genes coding for hundreds or thousands of proteins of unknown function (PUFs). In some cases, these coding sequences appear to be conserved across nearly all bacteria. Exploring the functional roles of these cases ideally requires an integrative, cross-species approach involving not only gene sequences but knowledge of interactions among their products. Protein interactions, studied at genome scale, extend genomics into the field of …