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 …

Expansion Of And Reclassification Within The Family Lachnospiraceae, Kelly N. Haas

Doctoral Dissertations

Many of the taxa in the family Lachnospiraceae are currently misclassified as Clostridium spp. Here attempt to rectify many of these issues, beginning with an in-depth genomic and physiologic analysis of Clostridium methoxybenzovorans, culminating in the assertion that is a heterotype of Clostridium indolis, followed by reclassification of the broader group in which this organism resides. We propose two novel genera, Lacriformis and Enterocloster, to reclassify this clade, this includes reclassification of Clostridium sphenoides, Clostridium indolis, Clostridium saccharolyticum, Clostridium celerecrescens, Clostridium xylanolyticum, Clostridium algidixylanolyticum, Clostridium aerotolerans, Clostridium amygdalinum, and …

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 …

Relationship Between Morphogenesis And Secretion In The Filamentous Fungus Aspergillus Nidulans, Lakshmi Preethi Yerra

Dissertations and Theses in Biological Sciences

Filamentous fungi have a long history in biotechnology for the production of food ingredients, pharmaceuticals and enzymes. The advancements made in recent years have earned filamentous fungi such as Aspergillus species a dominant place among microbial cell factories. Although the model fungus A. nidulans has been extensively studied, the genetic and regulatory networks that underlie morphogenesis and development have yet to be fully characterized. The Rho GTPases (Cdc42 and RacA) are one of the most important regulators of the morphogenetic processes among diverse eukaryotic organisms. Although the functions of these GTPases are relatively well-characterized, little is known about their downstream …

Improving Metabolic Engineering And Characterization Of Clostridium Thermocellum For Improved Cellulosic Ethanol Production, Beth Alexandra Papanek

Doctoral Dissertations

Biofules are an important option for humanity to move away from its dependence on fossil fuels. Transitioning from food crops to lignocellulosic alternatives for the production of biofuels is equally important. Most commonly, biofuels are produced using a crop such as corn or soybeans to feed sugars to the yeast, Saccharomyces cerevisiae for the fermentation of ethanol. Lignocellulosic biofuel production would eliminate the need for food crops and transition to biomass such as switchgrass, poplar, or corn stover. Currently, lignocellulosic biofuel production is limited primarily because of the cost of converting the biomass to fermentable sugars than can then be …

Chemokines And Peptides That Promote And Inhibit Cmv Entry, Elisabeth Anne Pitt

Masters Theses

Human cytomegalovirus (HCMV) causes morbidity and mortality in congenitally infected newborns, transplant recipients, and AIDS patients. Currently, there is no approved CMV vaccine to address these issues. In an effort to develop an alternative treatment to CMV we tested our hypothesis that heparan sulfate binding D-peptides would be effective against multiple HCMV strains in vitro and it would be effective in vivo against murine CMV (MCMV) (Chapter 1). We show that the D-peptide is able to reduce CMV infection in vitro and in vivo. Another approach to combating CMV infections is to neutralize pathogenic factors that contribute to CMV …

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 …

Genomic Diversity Of Pseudoalteromonas Atlantica From Geographically Distant Deep Marine Basins, Erika N. Youngquist

Chancellor’s Honors Program Projects

No abstract provided.

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) …

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 …

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 …

No Nonsense: The Protection Of Wild-Type Mrnas From Nonsense-Mediated Mrna Decay In Saccharomyces Cerevisiae, Krista Patefield

Dissertations and Theses in Biological Sciences

Gene regulation in eukaryotes is tightly controlled at multiple levels to ensure proper expression and cellular homeostasis. Misregulation of gene expression is a common source of genetic disease. One mechanism by which cells are able to control gene expression is through the synthesis and degradation of the mRNA molecules encoding the genes. The transcription and degradation of mRNA molecules controls the pool mRNAs that are available to the translational machinery. One of the well-studied mRNA decay pathways is the Nonsense-Mediated mRNA Decay pathway (NMD). Originally, NMD was discovered as a posttranscriptional mRNA surveillance mechanism responsible for the deadenylation-independent decapping and …

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 …

Epidemiology Of Select Species Of Filarial Nematodes In Free-Ranging Moose (Alces Alces) Of North America, Caroline Mae Grunenwald

Doctoral Dissertations

North American moose (Alces alces) are a culturally and economically valued species. Recent population declines raise concern for the survivability of this natural resource. The Minnesota population has experienced the most dramatic decline, with a 60% loss in total numbers since 2006. Nematode parasites, particularly some species of filarids, are important pathogens of moose and could be contributing to morbidity and mortality. This study investigates the eco-epidemiology of two filarial parasites of moose: Rumenfilaria andersoni and Elaeophora schneideri. By surveying cervid species from six U.S. states, we discovered R. andersoni was present in moose from all sample locations …

Method Assessment For Microalgae Quantification In Wastewater Treatment And Biofuel Production, Kristen S. Harrison

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

There is growing interest in the use of microalgae for wastewater treatment and biofuel production. However, there is not yet a reliable, user-friendly method of quantifying the biomass and lipid production of a large sample of algae. This study aims to establish and validate new methods for green microalgae quantification using the Microplate reader and the Coulter Counter. Chlorella vulgaris was chosen as the ‘ideal’ algal species for wastewater treatment and biofuel production due to its structure, lipid production, and pollution removal ability. Three traditional quantification methods -- microscope cell count, lipid separation, and chlorophyll extraction -- were compared to …

Influence Of Lactobacillus Rhamnosus Isolated From “Amabere Amaruranu” Cultured Milk On Adipogenesis, Justin E. Kotala

Electronic Theses and Dissertations

This study was performed to test the in vitro effects of a Lactobacillus rhamnosus isolate from “amabere amaruranu”, a traditional Kenyan cultured milk, on 3T3-L1 and Caco-2 cell lines. Cultures of fully mature 3T3-L1 adipocytes were treated with bacterial isolate cell extract (CE), filtered spent broth (FSB) from overnight bacterial culture, or with a PBS control. Expression levels of PPAR³1 and 2, C/EBP±, and ATGL proteins in 3T3-L1 cells were upregulated by FSB treatment. CE treatment did not affect protein expression levels. Expression of MTTP and SREBP-1c proteins in Caco-2 cells showed no change with either treatment. Optical density measurements …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …