Other Microbiology Commons^™

The Potential Of Endophytic Bacteria As The Biocontrol Agents Of Fusarium Proliferatum, Rima Ernia, Nisa Rachmania Mubarik, Lisdar Idwan Sudirman

Makara Journal of Science

Fusarium proliferatum decreases the productivity of shallot (Allium cepa L.). Endophytic bacteria are potential biocontrol agents in controlling the growth of F. proliferatum. This study aimed to select and characterize endophytic bacteria producing bioactive compounds that inhibit the growth of F. proliferatum. The endophytic bacteria used were isolated from the roots, stems, leaves, and soil of shallot plants from healthy and diseased shallot farming fields. The endophytic bacteria were selected using the dual culture method and extracted using ethyl acetate solvent. The results of the 16S rRNA identification suggested that isolate ABP5.2 is similar to Pseudomonas …

Annual Faculty Research Symposium 2022, Oakwood University

Proceedings

No abstract provided.

Structure-Function Studies Of The Trypanosome Mitochondrial Replication Protein Polib, Raveen Armstrong

Masters Theses

Trypanosoma brucei and related protists are distinguished from all other eukaryotes by an unusual mitochondrial genome known as kinetoplast DNA (kDNA) that is a catenated network composed of minicircles and maxicircles. Replication of this single nucleoid involves a release, replicate, and reattach mechanism for the thousands of catenated minicircles and requires at least three DNA polymerase (POLIB, POLIC and POLID) with similarity to E. coli DNA polymerase I. Like other proofreading replicative DNA polymerases, POLIB has both an annotated polymerase domain and an exonuclease domain. Predictive modelling of POLIB indicates that it has the canonical right hand …

Initial And Advanced Stages Of Microbiota Establishment Within The Tsetse Fly, Miguel Eduardo Medina Munoz

Graduate Theses, Dissertations, and Problem Reports

Symbiosis is a long-term physical association between two or more species, although little is known regarding its evolutionary origins, particularly at the genetic level. Tsetse flies are the vector of African trypanosomes, causative agents of Human and Animal African Trypanosomiases. Tsetse provide an ideal model for studying initial and advanced stages of symbiosis. Tsetse have a simple digestive tract microbiota primarily consisting of two bacteria; the ancient mutualist Wigglesworthia glossinidia and the recently acquired Sodalis glossinidius. This work presents a chronological study in evolutionary terms of the history of a microbial-insect association. First, I present concepts on symbiosis and …

Characterization Of The Overexpression Of The Native H+-Pumping Pyrophosphatase In The Microalga Picochlorum Soloecismus, Kimberly T. Wright

Biology ETDs

Microalgae are of interest for the creation of sustainable and cost competitive alternatives to petroleum-based fuels and chemicals. However, cultivation, extraction and processing of algal biomass requires improved yields to achieve economic feasibility. The advancement of microalgal biotechnology and various genetic engineering techniques allow the improvement of microalgae biomass for this purpose. Here, the characterization of the overexpression of the native vacuolar H+ pumping pyrophosphate (AVP1) in Picochlorum soloecismus was examined. AVP1 overexpression causes biomass increase in relevant plant crops. When overexpressed in this microalga it increases carbon storage in the form of starch in a closed laboratory photobioreactor. However, …

The Exploration Of Nanotoxicological Copper And Interspecific Saccharomyces Hybrids, Matthew Joseph Winans Phd

Graduate Theses, Dissertations, and Problem Reports

Nanotechnology takes advantage of cellular biology’s natural nanoscale operations by interacting with biomolecules differently than soluble or bulk materials, often altering normal cellular processes such as metabolism or growth. To gain a better understanding of how copper nanoparticles hybridized on cellulose fibers called carboxymethyl cellulose (CMC) affected growth of Saccharomyces cerevisiae, the mechanisms of toxicity were explored. Multiple methodologies covering genetics, proteomics, metallomics, and metabolomics were used during this investigation. The work that lead to this dissertation discovered that these cellulosic copper nanoparticles had a unique toxicity compared to copper. Further investigation suggested a possible ionic or molecular mimicry …

Hsp70-Mediated Regulation Of Hsf1 Transcriptional Activity In Saccharomyces Cerevisiae, Sara Peffer

Dissertations & Theses (Open Access)

In eukaryotic cells, protein homeostasis and cellular fitness is promoted by the transcription factor heat shock factor 1 (HSF1) during exposure to proteotoxic stress. HSF1 controls the basal and stress-induced expression of molecular chaperones and other protective targets. Dynamic regulation of HSF1 involves the major heat shock proteins Hsp70 and Hsp90. Recent advances in the understanding of this regulatory circuit in Saccharomyces cerevisiae have shown that the Hsp70 Ssa1 acts as a sensor for some proteotoxic stresses and is capable of a direct interaction with Hsf1. This work continues to explore the complex regulatory interaction between Hsf1 and Ssa1. I …

Thiol-Based Misfolding: Linking Redox Balance To Cytosolic Proteostasis, Ford Amy

Dissertations & Theses (Open Access)

The eukaryotic cytosolic proteome is vulnerable to changes in proteostatic and redox balance caused by temperature, pH, oxidants and xenobiotics. Cysteine-containing proteins are especially at risk as the thiol side chain is subject to oxidation, adduction and chelation by thiol-reactive compounds. All of these thiol-modifiers have been demonstrated to induce the heat shock response and recruit protein chaperones to sites of presumed protein aggregation in the budding yeast Saccharomyces cerevisiae. However, endogenous targets of thiol stress toxicity responsible for these outcomes are largely unknown. Furthermore, I hypothesize proteins identified as redox-active are prone to misfolding and aggregation by thiol-specific …

Protein Degradation Regulates Phospholipid Biosynthetic Gene Expression In Saccharomyces Cerevisiae, Bryan Salas-Santiago

Doctoral Dissertations

Transcriptional regulation of most phospholipid biosynthetic genes in Saccharomyces cerevisiae is coordinated by inositol and choline. Inositol affects phosphatidic acid (PA) intracellular levels. Opi1p interacts physically with PA and is the main repressor of the phospholipid biosynthetic genes. It is localized in the endoplasmic reticulum (ER) bound to the ER membrane protein Scs2p. When PA levels drop, Opi1p is translocated into the nucleus repressing most phospholipid biosynthetic genes. The OPI1 locus was identified in a screen looking for overproduction and excretion of inositol (Opi^-). Opi^- mutants are generally associated with a defect in …

Jmh Dissertation 2016.Pdf, Jennifer Hayashi

Jennifer Hayashi

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 …

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 …

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 …

Promoting Extracellular Matrix Crosslinking In Synthetic Hydrogels, Marcos M. Manganare

Masters Theses

The extracellular matrix (ECM) provides mechanical and biochemical support to tissues and cells. It is crucial for cell attachment, differentiation, and migration, as well as for ailment-associated processes such as angiogenesis, metastases and cancer development. An approach to study these phenomena is through emulation of the ECM by synthetic gels constructed of natural polymers, such as collagen and fibronectin, or simple but tunable materials such as poly(ethylene glycol) (PEG) crosslinked with short peptide sequences susceptible to digestion by metalloproteases and cell-binding domains. Our lab uses PEG gels to study cell behavior in three dimensions (3D). Although this system fosters cell …

How Many Particles Are Present In The Air? Bioaerosol Detection Using An Air Particle Counter, Angie Pamela Rivera, Parag Vaishampayan

STAR Program Research Presentations

Relative cleanliness in terms of particle abundance in spacecraft assembly facilities is determined by particle counts carried out in clean rooms during resting conditions. Particle counters assess total particles and particle size distribution, but do not distinguish inert particles from biological particles, which may include bacterial spores that are resistant to standard cleanroom sterilization procedures. Current cleanroom certifications do not fully assess the effects of human presence on spacecraft contamination since humans are known symbionts to enumerate microorganisms and assessments are performed at rest when there is no human presence. In this study, contamination risks and bioburden in spacecraft assembly …

Efficacy Of Ultraviolet Radiation To Control Lactic Acid Bacteria In Wine Must, Brian D. Williams

All Master's Theses

The use of shortwave ultraviolet (UV_c) radiation to control lactic acid bacteria (LAB) in wine production was studied. A simulated wine sterilizer was built using a commercially sourced ultraviolet (UV) sterilizer commonly used in aquariums and ponds. After growing cultures in test tubes, samples of five different species of LAB were introduced into white grape juice adjusted for brix and pH to match that of wine must commonly found in the Yakima Valley American Viticultural Area. The mixture was then agitated and allowed time to evenly distribute the bacteria throughout the juice. The juice was sent through the …

Characterizing The Response Of Multidrug-Resistant Klebsiella Pneumoniae Species To The Application Of A Phage Cocktail, Steven Liu

Symposium

Project Summary: The application of bacteriophages to treat bacterial infections is known as phage therapy, which takes advantage of bacteriophage’s natural ability to infect and lyse bacterial hosts. Phages have been shaped by billions of years of evolution to be highly specialized deliverers of bactericidal agents to the cytoplasm of their target bacteria. Ever since discovery of bacteriophages in 1915, phage therapy was recognized as a potentially powerful tool for eliminating bacterial infections. The effectiveness of phage therapy can be increased by creating a mixture of multiple phages to target a wider variety of bacterial strains. Furthermore, phage therapy has …

Characterizing The Human Vaginal Microbiome Using High-Throughput Sequencing, Jean Megan E. Macklaim

Electronic Thesis and Dissertation Repository

The human vaginal microbiome undoubtedly has a significant role in reproductive health and for protection from infectious organisms. Recent efforts to characterize the bacterial species of the vagina using molecular techniques have uncovered an unexpected diversity. Using high-throughput sequencing I sought to describe the structure and function of the vaginal microbiome under different physiological states including healthy, bacterial vaginosis (BV), post-menopausal vaginal atrophy, and acute vulvovaginal candidiasis (VVC).

Partial 16S rRNA gene sequencing revealed that healthy, asymptomatic women most often have vaginal biotas dominated by Lactobacillus iners or L. crispatus. In contrast, BV is a heterogeneous, highly diversified condition …

Analyzing Environmental Microbes For Genomic Regions Promoting Ionic Liquid Tolerance In E. Coli, Ann Nguyen, Alison Richins, Thomas Rüegg, Steven Singer, Michael Thelen

STAR Program Research Presentations

Ionic liquids (ILs) are promising as solvents to increase the efficiency of biofuel production; however, ILs are toxic to microbes used in the fermentation of liquid fuels. To engineer IL resistant biofuel hosts, environmental bacteria were screened for tolerance, and these were used to create gene libraries to test in E. coli. Future characterization of these libraries using molecular techniques will be used to identify genes that contribute IL-tolerance to transformed microbes.

A Messenger Molecule Governs Interdependency In An Evolved Pseudomonas Aeruginosa Biofilm Community, Thomas Macelliott Johnson

Honors Theses and Capstones

Biofilm populations are known to harbor great diversity, but the importance of this diversity is not fully understood. A likely contributor to this variation is the second messenger molecule cyclic-di-GMP: low levels associate with a planktonic lifestyle while high levels favor biofilm formation. In ongoing studies of an evolving biofilm population of Pseudomonas aeruginosa (PA), we observed extensive ecological diversification that may relate to this lifestyle switch. In PA, the gene bifA encodes a phosphodiesterase that is known to degrade cyclic-di-GMP and reduce biofilm. This gene was cloned onto a plasmid under control of an inducible promoter and the plasmid …

Letter From The Dean, Lalit Verma

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

No abstract provided.