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Functional And Structural Mimicry Of A-Kinase Anchoring Proteins By Human Adenovirus E1a, Cason R. King Feb 2018

Functional And Structural Mimicry Of A-Kinase Anchoring Proteins By Human Adenovirus E1a, Cason R. King

Electronic Thesis and Dissertation Repository

As an obligate intracellular parasite, human adenovirus (HAdV) must utilize host factors for survival and replication. Early during infection, its multifunctional E1A protein interacts with an impressive range of cellular target proteins to exert control over the cellular environment. Through these virus-host interactions, E1A massively reprograms both viral and cellular transcription to activate the other HAdV genes, downregulate the host’s immune response, and induce the cell cycle. Consequently, E1A converts the infected cell into a compliant state more amenable for HAdV replication, resulting from its numerous protein-protein interactions. I sought to examine E1A’s interaction with cellular protein kinase ...


Nutritional Regulation Of Sulfonamide Antibiotic Biodegradation By Microbacterium Sp. Strain C448, Tonya Malcolm Dec 2017

Nutritional Regulation Of Sulfonamide Antibiotic Biodegradation By Microbacterium Sp. Strain C448, Tonya Malcolm

Electronic Thesis and Dissertation Repository

Sulfonamide antibiotics are frequently released into the environment due to their widespread use in livestock production, imposing a potential selection pressure for the development and dissemination of sulfonamide resistance. Recently, a sulfonamide-degrading bacterium Microbacterium sp. Strain C448 was discovered, whose activity has the potential to be used as a sulfonamide removal strategy from agricultural soils. This research gains insight into the sulfonamide biodegradation pathway by 1) evaluating the nutritional regulation of sulfamethazine biodegradation and 2) undertaking a comparative proteomic analysis of cells grown in the presence and in the absence of sulfamethazine. The nutritional analyses revealed that increasing amounts of ...


Identification And Characterization Of Farr And Fare As A Regulator And Effector Of Fatty Acid Resistance In Staphylococcus Aureus, Heba Alnaseri Dec 2017

Identification And Characterization Of Farr And Fare As A Regulator And Effector Of Fatty Acid Resistance In Staphylococcus Aureus, Heba Alnaseri

Electronic Thesis and Dissertation Repository

Although Staphylococcus aureus is exposed to antimicrobial fatty acids on the skin, in nasal secretions and in abscesses, specific mechanisms for regulating gene expression and intrinsic resistance in response to these fatty acids have not been reported. Through in vitro selection for increased resistance of S. aureus to linoleic acid, I identified fatty acid resistant clone FAR7, where a single nucleotide polymorphism caused a His121Tyr substitution in an uncharacterized member of the TetR family of transcriptional regulators, which is divergently transcribed from a gene encoding a member of the resistance-nodulation-division superfamily of multi-drug efflux pumps. I named these ...


Urea As An Effective Nitrogen Source For Cyanobacteria, Kevin J. Erratt Oct 2017

Urea As An Effective Nitrogen Source For Cyanobacteria, Kevin J. Erratt

Electronic Thesis and Dissertation Repository

Urea use has grown substantially in the past half-century, with urea now accounting for > 50% of nitrogen fertilizer applications worldwide. The shift from inorganic nitrogen fertilizers to urea-based sources has coincided with the reappearance of cyanobacteria blooms in freshwaters. Here, we examined urea as a nitrogen source for three bloom-forming cyanobacteria species. We found that (1) urea was consumed more rapidly relative to inorganic nitrogen substrates, suggesting that cyanobacteria exhibit a preference for urea; (2) urea was consumed in excess of cellular requirements; and (3) urea may offer cyanobacteria a competitive edge over eukaryotic algae by enhancing light absorption capabilities ...


The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen Sep 2017

The Effect Of Diet On Midgut And Resulting Changes In Infectiousness Of Acmnpv Baculovirus In Trichoplusia Ni, Elizabeth Chen

Electronic Thesis and Dissertation Repository

The cabbage looper, Trichoplusia ni, a global generalist lepidopteran pest, has developed resistance to many synthetic and biological insecticides, requiring effective and environmentally acceptable alternatives. One possibility is the Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). This baculovirus is highly infectious for T. ni, with potential as a biocontrol agent, however, its effectiveness is strongly influenced by dietary context. In this study, microscopy and transcriptomics were used to examine how the efficacy of this virus was affected when T. ni larvae were raised on different diets. Larvae raised on potato host plants had lower chitinase and chitin deacetylase transcript levels and thickened ...


Examination Of Bcaa Transport And Synthesis In Staphylococcus Aureus, Julienne Kaiser Aug 2017

Examination Of Bcaa Transport And Synthesis In Staphylococcus Aureus, Julienne Kaiser

Electronic Thesis and Dissertation Repository

Staphylococcus aureus is a human pathogen capable of causing infections that range from mild skin and soft tissue infections to severe infections of the bone, muscle, heart, and lung. To survive and thrive in such diverse host environments, S. aureus must maintain sufficient levels of metabolites and cofactors to support virulence determinant production and replication. The branched-chain amino acids (BCAAs; Ile, Leu, Val) represent an important group of nutrients for S. aureus metabolism, as they are required for protein synthesis and synthesis of membrane branched-chain fatty acids (BCFAs), which are important for S. aureus environmental adaptation. Moreover, the BCAAs are ...


Developing A Plant Virus-Based Expression System For The Expression Of Vaccines Against Porcine Reproductive And Respiratory Syndrome Virus, Hong Hanh Tran Jul 2017

Developing A Plant Virus-Based Expression System For The Expression Of Vaccines Against Porcine Reproductive And Respiratory Syndrome Virus, Hong Hanh Tran

Electronic Thesis and Dissertation Repository

Virus-based expression systems have been widely exploited for the production of recombinant proteins in plants during the last three decades. Advances in technology have boosted scale-up manufacturing of plant-made pharmaceuticals to high levels, via the complementation of transient expression and viral vectors. This combination allows proteins of interest to be produced in plants within a matter of days and thus, is well suited for the development of plant-made vaccines or therapeutics against emerging infectious diseases and potential bioterrorism agents. Several plant-based products are currently in varying stages of clinical development. To investigate the viability of virus-based expression systems for plant-made ...


Disturbance And The Community Composition Of Arbuscular Mycorrhizal Fungi In Ontario Tallgrass Prairies, Sarah N. Allan Jul 2017

Disturbance And The Community Composition Of Arbuscular Mycorrhizal Fungi In Ontario Tallgrass Prairies, Sarah N. Allan

Electronic Thesis and Dissertation Repository

Arbuscular mycorrhizal fungi (Glomeromycota) form beneficial symbiotic relationships with the majority of land plants, especially in grasslands. Tallgrass prairies in Ontario are an endangered plant community currently being restored on former agricultural land. The objectives of my study were to determine if there were differences in the communities of Glomeromycota between disturbed and undisturbed tallgrass prairies in Ontario and if there were any potential indicator taxa for the ends of the disturbance spectrum. A molecular approach using DNA derived from soil samples was used to compare species composition between disturbed and undisturbed tallgrass prairies. A total of 177 operational taxonomic ...


Characterizing The Interaction Between Human Adenovirus E1a And The Transcriptional Repressor Bs69, Ali Zhang May 2017

Characterizing The Interaction Between Human Adenovirus E1a And The Transcriptional Repressor Bs69, Ali Zhang

Electronic Thesis and Dissertation Repository

Protein products of the Early Region 1A (E1A) gene in human adenovirus 5 (HAdV-5) are the first viral proteins expressed upon adenovirus infection. E1A disrupts many cellular physiological events by binding to and regulating an impressive number of host factors. Of particular interest is BS69, a repressor of E1A transactivation. Due to the strong interaction observed between E1A and BS69, I hypothesize that these two proteins function together to disrupt gene expression within an infected cell.

Using in silico modelling and a series of yeast two-hybrid assays, I determined that residues 112-119 of HAdV-5 E1A is the minimal interacting region ...


Investigating Adenovirus E1a As An Rna Polymerase Ii C-Terminal Domain Mimic And Its Role In Transcription Activation, Kristianne Jc Galpin May 2017

Investigating Adenovirus E1a As An Rna Polymerase Ii C-Terminal Domain Mimic And Its Role In Transcription Activation, Kristianne Jc Galpin

Electronic Thesis and Dissertation Repository

Viruses rely on host cell machinery, often mimicking cellular components, in order to circumvent host cell defenses and hijack cellular processes. DNA viruses, such as human Adenovirus (hAdV), rely on RNA Polymerase II (RNAPII) to transcribe viral genes. RNAPII has a C-terminal domain (CTD), made up of highly conserved heptad repeats of tyrosine-serine-proline-threonine-serine-proline-serine (YSPTSPS). Post-translational modifications of residues within the CTD, including phosphorylation, coordinates the transcription cycle. Several viruses, including Human Immunodeficiency Virus (HIV), Human Cytomegalovirus (hCMV), Epstein-Bar Virus (EBV) and Herpes Simplex Virus (HSV), modify the phosphorylation state of the RNAPII CTD by hijacking cellular cyclin dependent kinases (CDKs ...


Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke Feb 2017

Microbial Repopulation Following In Situ Star Remediation, Gavin Overbeeke

Electronic Thesis and Dissertation Repository

In situ STAR (Self-sustaining Treatment for Active Remediation) is an emerging remediation technology which uses smouldering combustion to destroy nonaqueous phase liquid (NAPL) contamination in the subsurface. Since STAR smouldering travels through contaminated soils slowly (~0.5 to 5 m/day) and subjects them to high temperatures (400–1000°C), it is expected that this technology will thoroughly dry and sterilize the zones which it treats. Further, soils surrounding the treatment zone which are not smouldered will be heated, although not smouldered, by virtue of their proximity to STAR, impacting microbial communities within them. Therefore, the objectives of this work ...


Species Pluralism: Conceptual, Ontological, And Practical Dimensions, Justin Bzovy Nov 2016

Species Pluralism: Conceptual, Ontological, And Practical Dimensions, Justin Bzovy

Electronic Thesis and Dissertation Repository

Species are central to biology, but there is currently no agreement on what the adequate species concept should be, and many have adopted a pluralist stance: different species concepts will be required for different purposes. This thesis is a multidimensional analysis of species pluralism. First I explicate how pluralism differs monism and relativism. I then consider the history of species pluralism. I argue that we must re-frame the species problem, and that re-evaluating Aristotle's role in the histories of systematics can shed light on pluralism. Next I consider different forms of pluralism: evolutionary and extra-evolutionary species pluralism, which differ ...


Development And Performance Evaluation Of An Antibody-Based Technology For Detection Of E. Coli O157 In Meat Samples And Its Potential Evolution Using Antibody Engineering, Yadira Tejeda Saldaña Sep 2016

Development And Performance Evaluation Of An Antibody-Based Technology For Detection Of E. Coli O157 In Meat Samples And Its Potential Evolution Using Antibody Engineering, Yadira Tejeda Saldaña

Electronic Thesis and Dissertation Repository

Escherichia coli O157 is a persistent pathogen linked to food and waterborne infectious outbreaks with severe health consequences such as hemorrhagic colitis and hemolyticuremic syndrome (HUS). Because it is considered one of the major pathogens that contributes to the global burden of foodborne disease, its early detection within the food chain is an important milestone towards reducing foodborne diseases and economic losses due to contaminated food. Herein, the development and validation of a lateral flow immunoassay (LFIA) point-of-care (POC) device is described. Application of the LFIA test kit was focused on detection of E. coli O157 in raw meat products ...


Hemolytic Activity In The Euryhaline Fish-Killing Phytoflagellate Prymnesium Parvum Under Environmental Stresses, Christine Dulal-Whiteway Sep 2016

Hemolytic Activity In The Euryhaline Fish-Killing Phytoflagellate Prymnesium Parvum Under Environmental Stresses, Christine Dulal-Whiteway

Electronic Thesis and Dissertation Repository

Harmful algal blooms (HABs) are vast expanses of noxious or toxic phytoplankton that periodically dominate coastal ocean waters or freshwater systems. An especially damaging type of HAB are the species that kill fish. In this thesis, a potentially invasive marine fish-killing flagellate, Prymnesium parvum, was investigated for its tolerance to freshwater conditions. This species has invaded some freshwater systems in the southern United States. The thesis examines if the growth rate and toxicity of Prymnesium parvum remain high under low salinities similar to freshwater systems. A hemolytic lysis assay was used as a proxy for toxicity. The findings presented here ...


Iron Acquisition Strategies Employed By Staphylococcus Lugdunensis, Jeremy R. Brozyna Aug 2016

Iron Acquisition Strategies Employed By Staphylococcus Lugdunensis, Jeremy R. Brozyna

Electronic Thesis and Dissertation Repository

Iron is crucial for many cellular processes including DNA synthesis and respiration. The majority of iron in mammals is in heme within hemoproteins, inside cells, or transported through circulation by the glycoprotein transferrin, which constitutes the greatest iron source in serum. Limiting iron availability is an important facet of nutritional immunity to help prevent infection.

Staphylococcus lugdunensis is a human skin commensal and opportunistic pathogen capable of causing a variety of infections, including particularly aggressive endocarditis. It is an emerging pathogen with elevated virulence compared to other species of coagulase-negative staphylococci. The versatility of S. lugdunensis to infect multiple niches ...


Oncolytic Virus Therapy For The Treatment Of Metastatic Ovarian Cancer, Jessica Tong Apr 2016

Oncolytic Virus Therapy For The Treatment Of Metastatic Ovarian Cancer, Jessica Tong

Electronic Thesis and Dissertation Repository

The management of patients with epithelial ovarian cancer (EOC) faces two major challenges which standard treatments fail to effectively address: 1) Diffuse metastasis as a consequence of late stage diagnosis and 2) intra-tumoral heterogeneity, which fuels tumor evolution and drives the acquisition of chemotherapeutic resistance. In this thesis, we tested new therapeutic strategies using a 3-dimensional in vitro spheroid culture model that mimics key steps of epithelial ovarian cancer metastasis; and another model that mimics both temporal and cellular heterogeneity by establishing multiple cell lines from a single patient over the course of disease progression. Using these models, we investigated ...


At The Interface Of Glycolipids And Glycoproteins In The Two Gastro-Intestinal Pathogens Campylobacter Jejuni And Helicobacter Pylori, Najwa Zebian Apr 2016

At The Interface Of Glycolipids And Glycoproteins In The Two Gastro-Intestinal Pathogens Campylobacter Jejuni And Helicobacter Pylori, Najwa Zebian

Electronic Thesis and Dissertation Repository

Campylobacter jejuni and Helicobacter pylori are phylogenetically related human gastro-intestinal pathogens. C. jejuni colonizes the intestine and is the leading cause of bacterial gastroenteritis worldwide. H. pylori colonizes the stomach of half the world’s population, causing gastritis, gastric ulcers and gastric cancer. Both pathogens express glycoproteins and glycolipids (capsule, lipooligosaccharide or lipopolysaccharide (LPS)) that are important in pathogenesis. Sugar units from capsule or LPS can modify proteins in several bacteria. We reasoned that this may occur in C. jejuni and H. pylori as means to diversify their surface glycosylation and aid in colonization, immune evasion and virulence.

The putative ...


Structural And Functional Studies Of The Heptose Modifying Enzymes That Play A Role In Campylobacter Jejuni Virulence., Heba Soliman Barnawi Jan 2016

Structural And Functional Studies Of The Heptose Modifying Enzymes That Play A Role In Campylobacter Jejuni Virulence., Heba Soliman Barnawi

Electronic Thesis and Dissertation Repository

Campylobacter jejuni is a major cause of gastroenteritis in humans. The capsule of some species contains unique modified heptoses. Heptose modification was elucidated for C. jejuni NCTC11168 and 18-176, and novel epimerases and reductases essential for the heptose modification were identified. We hypothesized that heptose modifying enzymes in C. jejuni have specific catalytic residues that allow for substrate and product specificity. Substrate synthesis, structural modeling, point mutations, and enzymatic analysis have been applied to map the active sites. Putative catalytic residues showed substrate and/or product specificity. The epimerases structures were solved by crystallography done by our collaborator. We also ...


Recombinase-Based In Vivo Expression Technology Identifies A Streptococcus Pyogenes Bacteriocin Important For Niche Adaptation In The Nasopharynx, Brent D. Armstrong Nov 2015

Recombinase-Based In Vivo Expression Technology Identifies A Streptococcus Pyogenes Bacteriocin Important For Niche Adaptation In The Nasopharynx, Brent D. Armstrong

Electronic Thesis and Dissertation Repository

Streptococcus pyogenes is a Gram-positive, human-specific bacterial pathogen with the ability to cause a wide range of diseases from strep throat to necrotizing fasciitis and toxic shock syndrome. In addition, S. pyogenes may also induce post-streptococcal sequelae including rheumatic fever, acute glomerulonephritis, and reactive arthritis. Although primarily recognized as a pathogen, S. pyogenes also colonizes the skin and throat often without causing disease, and while numerous surface adhesions are important to attach to these surfaces, additional factors important for colonization and persistence by S. pyogenes are poorly understood. In addition to host defence mechanisms, the upper respiratory tract also contains ...


Iron Acquisition Mechanisms And Their Role In Staphylococcus Aureus Survival And Virulence, Jessica R. Sheldon Oct 2015

Iron Acquisition Mechanisms And Their Role In Staphylococcus Aureus Survival And Virulence, Jessica R. Sheldon

Electronic Thesis and Dissertation Repository

To microbes and humans alike, iron is both essential, and potentially toxic, where homeostatic concentrations must be stringently maintained. Within the iron-restricted host, the survival and proliferation of microbial invaders is contingent upon exploiting the host iron pool. Staphylococcus aureus is a formidable pathogen, whose success is partly attributable to its multiple, and often redundant mechanisms for acquiring iron. A decade of research in staphylococcal iron acquisition has identified several uptake mechanisms, including, but not limited to, the elaboration of high-affinity iron scavenging siderophores (staphyloferrins A (SA) and B (SB)) and the expression of an iron-regulated surface determinant (Isd) pathway ...


Characterization Of Fatty Acid Resistant Staphylococcus Aureus Mutants Containing Snps In Cvfa, Melissa N. Loyzer Sep 2015

Characterization Of Fatty Acid Resistant Staphylococcus Aureus Mutants Containing Snps In Cvfa, Melissa N. Loyzer

Electronic Thesis and Dissertation Repository

Upon colonization, Staphylococcus aureus must withstand the actions of many host defense mechanisms, including the unsaturated free fatty acids (uFFAs) secreted in sebum. Linoleic acid, a representative uFFA, is toxic to S. aureus at concentrations ≥50 µM; however, we selected for mutants capable of growing at elevated concentrations of linoleic acid. Five mutants had single nucleotide polymorphisms (SNPs) in the cvfA gene encoding an RNase that is a component of the RNA degradosome, and expression of the SNP-containing cvfA genes from a plasmid engendered S. aureus with high level resistance to linoleic acid. The SNPs were located within a region ...


Characterizing The C-Terminal Region Of Human Adenovirus E1a: An Undiscovered Country, Michael J. Cohen Sep 2015

Characterizing The C-Terminal Region Of Human Adenovirus E1a: An Undiscovered Country, Michael J. Cohen

Electronic Thesis and Dissertation Repository

Human Adenovirus (HAdV) E1A is the first protein expressed during viral infection. The primary function of E1A is to reprogram the cell for viral replication, but it is additionally capable of transforming primary rodent cells in co-operation with other oncogenes such as HAdV E1B. Despite extensive study, little is known about the function and cellular targets of the C-terminal region of E1A. Importantly, this region is required for the transforming ability of E1A with E1B, but can also suppress transformation with Ras. Previous studies showed that interaction with the C-terminal Binding Protein (CtBP) plays a role in both functions described ...


Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur Aug 2015

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected ...


Clinical And Mechanistic Insights Into Novel Probiotic Functions And Formulations, Jordan Bisanz Jul 2015

Clinical And Mechanistic Insights Into Novel Probiotic Functions And Formulations, Jordan Bisanz

Electronic Thesis and Dissertation Repository

Using a combination of hypothesis and discovery based approaches, the goal of this thesis was to better describe novel probiotic functions and their mechanisms while striving to better understand the effect of formulation on Bifidobacterium animalis subsp. lactis, Lactobacillus paracasei and L. rhamnosus.

Using RNA-Seq, a bacterial metatranscriptome analysis of a commonly consumed probiotic yogurt showed that the organisms adapted to storage time and flavor additions. This led to the discovery that in addition to the probiotic health benefits, members of the L. casei group (L. rhamnosus and L. paracasei) produce volatile sulfur compounds mediated by a novel sulfur/taurine ...


Functional Characterization Of P3n-Pipo Protein In The Potyviral Life Cycle, Hoda Yaghmaiean Jul 2015

Functional Characterization Of P3n-Pipo Protein In The Potyviral Life Cycle, Hoda Yaghmaiean

Electronic Thesis and Dissertation Repository

Potyviruses represent the largest genus of plant-infecting viruses and include many agriculturally important viruses such as Turnip mosaic virus (TuMV), Soybean mosaic virus (SMV) and Plum pox virus (PPV). The potyviral genome consists of a large open reading frame (ORF) and a small ORF owing to a translational or transcriptional slippage in the P3 cistron. The polyproteins encoded by these two ORFs are proteolytically processed into 11 mature proteins. Recent studies have shown that P3N-PIPO, the frameshift resulting protein, is a plasmodesmata (PD)-located protein and involved in potyviral cell-to-cell movement by mediating the targeting of the potyviral CI protein ...


Streptococcus Pyogenes Superantigens: Studies Into Host Specificity And Functional Redundancy, Adrienne T. Wakabayashi Jun 2015

Streptococcus Pyogenes Superantigens: Studies Into Host Specificity And Functional Redundancy, Adrienne T. Wakabayashi

Electronic Thesis and Dissertation Repository

Streptococcus pyogenes is a human-specific globally prominent bacterial pathogen that secretes extremely potent exotoxins known as superantigens. Superantigens function to overstimulate T lymphocytes, capable of inducing excessive cytokine responses, potentially leading to toxic shock syndrome. Each strain of S. pyogenes encodes multiple distinct superantigens, yet the reasons why S. pyogenes retains multiple superantigens has remained elusive. Using a murine model of acute nasopharyngeal infection, the role of each superantigen encoded by S. pyogenes MGAS5005 was evaluated using isogenic superantigen-deletion or -complemented strains, and passive immunization with superantigen-neutralizing antibodies. The superantigen SpeG, and likely SpeJ, were not required for infection. However ...


Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf May 2015

Granulocyte Colony-Stimulating Factor: Its Role In Gut-Homing Macrophage Generation And Colitis, And Production By Probiotics, Shahab Meshkibaf

Electronic Thesis and Dissertation Repository

The pleiotropic cytokine granulocyte-colony stimulatory factor (G-CSF) is mainly required for the generation of neutrophils, but its role in macrophage generation has also been reported. In addition, G-CSF is effective for the down-regulation of inflammatory cytokines and ameliorating gut disorders, such as colitis. However, the G-CSF function in macrophage generation and gut immunity remains unclear. The first focus of this thesis was to assess the role of G-CSF in macrophage generation and its contribution to gut immunity. G-CSF was found to promote the generation of Gr-1high/F4/80+ macrophages in macrophage (M)-CSF-treated bone marrow cells, most likely through suppressing ...


Genomic Analyses Of Paenibacillus Polymyxa Cr1, A Bacterium With Potential Applications In Biomass Degradation And Biofuel Production, Alexander W. Eastman May 2015

Genomic Analyses Of Paenibacillus Polymyxa Cr1, A Bacterium With Potential Applications In Biomass Degradation And Biofuel Production, Alexander W. Eastman

Electronic Thesis and Dissertation Repository

Lignin is a polyphenolic heteropolymer constituting between 18 to 35% of lignocellulose and is recognized as preventative of cellulosic biofuel commercialization. Paenibacillus polymyxa CR1 was isolated from naturally degrading corn stover and shown to produce alcohols using lignin as a sole carbon source. Genome sequencing and comparative genomics of P. polymyxa CR1 identified two homologs, a Dyp-type peroxidase and a laccase, which have previously been implicated in lignin metabolism in other bacteria. Knockout mutants of the identified genes displayed no growth deficiency and P. polymyxa CR1 is incapable of metabolizing common aromatic intermediates of lignin, suggesting the bacterium employs a ...


Characterization Of Seed Transmission Of Soybean Mosaic Virus In Soybean, Tanvir Bashar Apr 2015

Characterization Of Seed Transmission Of Soybean Mosaic Virus In Soybean, Tanvir Bashar

Electronic Thesis and Dissertation Repository

Infection by Soybean mosaic virus (SMV) is recognized as a serious, long-standing threat in most soybean (Glyince max (L.)Merr.) producing areas of the world. The aim of this work was to understand how SMV transmits from infected soybean maternal tissues to the next generation by investigating the possible routes and amounts of seed transmission of SMV. Analysis of seeds at various reproductive stages revealed that SMV infects all parts of the seed, including the embryo, cotyledon and testa. In situ hybridization and immunofluorescence studies detected the presence of negative sense RNA and dsRNA in the suspensor base regions and ...


The Role Of Streptococcus Salivarius As A Modulator Of Homeostasis In The Oral Cavity, Kyle W. Macdonald Mar 2015

The Role Of Streptococcus Salivarius As A Modulator Of Homeostasis In The Oral Cavity, Kyle W. Macdonald

Electronic Thesis and Dissertation Repository

The oral cavity contains many different surfaces all colonized by prokaryotes, of which over 700 have been identified. While almost all people have some degree of plaque formation, the more concerning diseases of caries, candidiasis and periodontal disease afflict many patients and represent a major public health concern. As these are all diseases which have a component attributable to parts of the microbiota, efforts to manipulate the microbes has until recently involved use of antimicrobial agents. However, due to side effects, resistance and failure to restore homeostasis, this approach is limited. As an alternative, the administration of beneficial microbes (probiotics ...