Microbiology Commons^™

Figure 3, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Figure S2, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Figure S1, Marquette University, Lisa Petrella

Mikeworth 2023

No abstract provided.

Molecular Regulation Of The Salicylic Acid Hormone Pathway In Plants Under Changing Environmental Conditions, Christina A. M. Rossi, Eric J. R. Marchetta, Jong Hum Kim, Christian Castroverde

Biology Faculty Publications

Salicylic acid (SA) is a central plant hormone mediating immunity, growth, and development. Recently, studies have highlighted the sensitivity of the SA pathway to changing climatic factors and the plant microbiome. Here we summarize organizing principles and themes in the regulation of SA biosynthesis, signaling, and metabolism by changing abiotic/biotic environments, focusing on molecular nodes governing SA pathway vulnerability or resilience. We especially highlight advances in the thermosensitive mechanisms underpinning SA-mediated immunity, including differential regulation of key transcription factors (e.g., CAMTAs, CBP60g, SARD1, bHLH059), selective protein–protein interactions of the SA receptor NPR1, and dynamic phase separation of the recently identified …

Teloportwrapper: A New Tool For Understanding The Dynamic World Of Fungal Telomere Ends, Trey Stansfield

Mahurin Honors College Capstone Experience/Thesis Projects

Telomeres are repetitive DNA sequence motifs found at eukaryote chromosome ends. Telomeres help protect chromosome ends from DNA damage and promote chromosome stability. Chromosomes play important roles in aging, mutation, and cancer. Eukaryotic pathogens also use telomeres to mutate and manage virulence genes. In response to chromosome end breakage newly formed telomeres, called de novo telomeres, are formed to recreate the lost telomere and sub-telomeric regions.

Magnaporthe oryzae is a fungal pathogen which causes wheat blast, a deadly plant disease in wheat. Magnaporthe oryzae is also known for its highly variable sub-regions which show high amounts of induced variability due …

Evaluation Of Ionic Liquid Treatment As An Alternative To Chemical Fixation And Dehydration In The Preparation Of Biofilms For Scanning Electron Microscopy, Molly Shreve

Mahurin Honors College Capstone Experience/Thesis Projects

Scanning electron microscopes (SEM) give researchers the ability to observe very small features on biological specimens at the nanometer scale, which is a much higher resolution than what can be obtained with a light microscope. To be observed under SEM, unlike light microscopes, samples must be dry, conductive, and able to withstand electron bombardment. Preparation methods have been developed that work well for samples composed mainly of proteins and lipids, but these fail for samples that are predominantly carbohydrates, such as bacterial biofilms. When carbohydrates of these biofilms are dehydrated, they tend to shrink and collapse, and their normal hydrated …

A Novel Therapeutic Approach To Regulate Carex8 Protein Expression Through E6-Conjugated Cell Penetrating Peptides, Jared D. Compaleo

Browse all Theses and Dissertations

Adenovirus is a human pathogen that causes cold like symptoms in healthy individuals, which could be lethal in pediatrics and the immunocompromised. In polarized epithelia, adenovirus uses the eight-exon isoform of the Coxsackievirus and Adenovirus Receptor (CAREx8) on the apical surface, to facilitate infection. CAREx8 protein expression level is regulated by the scaffolding protein MAGI-1, using two of its PSD95/Dlg-1/ZO-1 (PDZ) domains: PDZ2 and PDZ4. We previously showed that CAREx8 is degraded after interaction with PDZ4 and rescued following interaction with PDZ2. We then developed a PDZ2 binding decoy molecule (E6) that blocks the interaction between CAREx8 and PDZ2, which …

Beer-Spoilage Bacterial Strains In Large And Small Corporations In Breweries, Darlene A. Villalobos Cazares, Xena Pastor-Nuila, Ernesto Acosta, Johana Cruz-Lopez

Humboldt Journal of Microbiology

Bacteria-spoilage strains are the root cause of unwanted flavors and unaesthetic appearances of beer. This accidental introduction of bacteria is causing economic loss to businesses and is affecting the health and loyalty of the breweries' consumers. The two most studied strains are from the genera Pediococcus and Lactobacillus are a result of either primary or secondary contamination from the production process. Craft beers, such as Hazy Beers, produced by small-scale breweries are more prone to spoilage than commercial beers produced by large-scale breweries. The goal of this study is to test for the presence of bacteria-spoilage strains in small-scale breweries …

Analysis Of A Cathepsin Protease In Normal Development And Tumor Metastasis In Drosophila Melanogaster, Lindsey Fannin

Mahurin Honors College Capstone Experience/Thesis Projects

Cysteine cathepsins are an important class of fifteen proteases with involvement in normal development and tumor progression. To better understand their contribution to these processes, the cathepsin L protease in Drosophila melanogaster was studied. In part one of this project, the role of this cathepsin in the normal development of Drosophila wings was analyzed. The GAL4/UAS-system and RNAi were used to downregulate this cathepsin in various regions of the wing and progeny were inspected for phenotypic irregularities. An abnormal phenotype of curved wings was found and hypothesized to be a result of apoptosis. Further experimentation will be required to prove …

Botanical Assessment Of Remnant Floodplain Habitats Along Plaster Creek, Kent County, Michigan: Assessing Changes Since The 1890s, Haley R. Weesies, Garrett Crow, David Warners

Faculty and Professional Research

Plaster Creek, a tributary of the Grand River, drains a 58-square mile watershed in Kent County, Michigan. Its headwaters originate in the agriculturally dominated southwestern portion of the county, and then it meanders through residential, commercial, and urban areas of Kentwood and Grand Rapids before it empties into the Grand River about one mile south of downtown Grand Rapids. Much of Plaster Creek’s original floodplain, like the rest of its watershed, has been drastically altered and degraded over time due to the development of residential neighborhoods, commercial properties, agriculture, and industrial zones. Floodplains house unique assemblages of Michigan’s native biodiversity …

Dcaf14 Regulates Cdt2 To Promote Set8-Dependent Replication Fork Protection, Neysha Tirado-Class, Caitlin Hathaway, Anthony Nelligan, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

DDB1- and CUL4-associated factors (DCAFs) CDT2 and DCAF14 are substrate receptors for Cullin4–RING E3 ubiquitin ligase (CRL4) complexes. CDT2 is responsible for PCNA-coupled proteolysis of substrates CDT1, p21, and SET8 during S-phase of cell cycle. DCAF14 functions at stalled replication forks to promote genome stability, but the mechanism is unknown. We find that DCAF14 mediates replication fork protection by regulating CRL4CDT2 activity. Absence of DCAF14 causes increased proteasomal degradation of CDT2 substrates. When forks are challenged with replication stress, increased CDT2 function causes stalled fork collapse and impairs fork recovery in DCAF14-deficient conditions. We further show that stalled fork protection …

Otud5 Limits Replication Fork Instability By Organizing Chromatin Remodelers, Angelo De Vivo, Hongseon Song, Yujin Lee, Neysha Tirado-Class, Anthony Sanchez, Sandy D. Westerheide, Huzefa Dungrawala, Younghoon Kee

Molecular Biosciences Faculty Publications

Proper regulation of replication fork progression is important for genomic maintenance. Subverting the transcription-induced conflicts is crucial in preserving the integrity of replication forks. Various chromatin remodelers, such as histone chaperone and histone deacetylases are known to modulate replication stress, but how these factors are organized or collaborate are not well understood. Here we found a new role of the OTUD5 deubiquitinase in limiting replication stress. We found that OTUD5 is recruited to replication forks, and its depletion causes replication fork stress. Through its C-terminal disordered tail, OTUD5 assembles a complex containing FACT, HDAC1 and HDAC2 at replication forks. A …

The Identification Of Two M20b Family Peptidases Required For Full Virulence In Staphylococcus Aureus, Nathanial James Torres, Devon Rizzo, Maria A. Reinberg, Mary-Elizabeth Jobson, Brendan C. Totzke, Jessica K. Jackson, Wenqi Yu, Lindsey Neil Shaw

Molecular Biosciences Faculty Publications

We have previously demonstrated that deletion of an intracellular leucine aminopeptidase results in attenuated virulence of S. aureus. Herein we explore the role of 10 other aminopeptidases in S. aureus pathogenesis. Using a human blood survival assay we identified mutations in two enzymes from the M20B family (PepT1 and PepT2) as having markedly decreased survival compared to the parent. We further reveal that pepT1, pepT2 and pepT1/2 mutant strains are impaired in their ability to resist phagocytosis by, and engender survival within, human macrophages. Using a co-infection model of murine sepsis, we demonstrate impairment of dissemination and survival …

Kom-Butcher Of Pathogens, Mel Peña, Yazmin Chamu, Laura Lea Davis

Humboldt Journal of Microbiology

The antimicrobial properties of kombucha are not well understood, but it is believed that they can be used against foodborne pathogens. In this study, its effectiveness was tested against two common food-borne and one yeast pathogens (E. coli, S. aureus, and C. auris). Three popular store-bought kombuchas (GT Synergy, Moss Beach, and Health-Aide Raw) and one home-brewed kombucha were used to study the antimicrobial properties of kombucha. Several nutrient broth tubes were individually inoculated with the microbes in question and were treated with kombucha (Figures 1-3). There were indications of bacteria settling at the bottom of all tubes except the …

Effects Of Fasting On The Oral Microbiome, Youyuan Wang, Leonard Moreno, Fernando Reyes

Humboldt Journal of Microbiology

Humans are mostly made up of microbes. Multiple studies have estimated that bacterial cells outnumber human cells in the body, with our digestive systems harboring the highest concentrations of bacterial life. The oral microbiome is densely populated and of significant physiological importance. These microbial communities maintain tooth and gum health, aids in pre-digestion of foods, and even plays a defensive role — guarding their host from external threats that may lead to oral and systemic pathologies. Studies have shown that fasting can affect the gut microbiome, but there is currently insufficient research on how fasting intervals can affect the oral …

Diatom Abundance And Diversity Across The Arcata Wastewater Treatment Plant And Wildlife Sanctuary, Rhiannon Red Bird, Anna K. Curry, Brandy R. Ayon, Kellie N. Pierson

Humboldt Journal of Microbiology

Wastewater management is an essential component of modern society that is necessary for reducing human environmental impact, particularly in aquatic ecosystems. In Humboldt County, California, the Arcata Wastewater Treatment Plant and Wildlife Sanctuary (Arcata Marsh) is a model for other wastewater treatment plants worldwide to treat waste naturally, reducing the use of chemicals. This wastewater is then discharged into the Humboldt Bay. It is well known how treatment helps remove harmful waste materials, but it has not been investigated how phytoplankton diversity is affected before, during, and after treatment. Phytoplankton are primary producers that are responsible for carbon sequestration and …

Full Issue

Humboldt Journal of Microbiology

No abstract provided.

Kirby-Bauer Disc Diffusion Method Indicates Absence Of Antimicrobial Properties In Ariolimax Columbianus Mucus, Elsa Balfe, Elizabeth Kowalski, Stephanie A. Leavitt

Humboldt Journal of Microbiology

Antibiotic resistance is a rapidly accelerating epidemic demanding novel approaches. Gastropod mucus has been shown to possess antimicrobial properties and could potentially be used as an ingredient in antibiotic development. However, whether the mucus of Ariolimax columbianus, the banana slug, also displays antimicrobial properties is unknown. In this study, we investigated whether the mucus of A. columbianus is resistant to Escherichia coli (E.coli), Streptococcus aureus (S.aureus), and Klebsiella pneumoniae (K.pneumoniae), three medically relevant strains of bacteria. Specimens were collected from a coniferous forest and isolated for downstream mucus extraction. We spread uniform concentrations of our bacteria on Mueller-Hinton agar plates …

Testing Ssa4:Ade3 Reporters For Mcs Screening, Karah Edmonds, Rebecca Adams

Science University Research Symposium (SURS)

In eukaryotic cells, after transcription, mRNA is escorted from the nucleus to the cytoplasm to be translated. This process, called mRNA export, is essential for gene expression. However, when the cell exists in stressful conditions, mRNA export becomes regulated, and only select transcripts, including the stress-responsive SSA4 mRNA, can be exported. This project aims to uncover the mechanism of selective SSA4 mRNA export by generating a reporter that enables phenotypically visible expression under stressful conditions. Specifically, the ADE3 ORF was placed under the regulatory sequence of SSA4, which was anticipated to induce a red color for colonies only following stress. …

Application Of Nitrate To An Anaerobic Subsurface Bioremediation, Cassie Marie Roberts

Masters Theses

"The highly contaminated subsurface matrix of the Baird and McGuire Superfund site is currently threatening the health and safety of the surrounding environment of Holbrook, MA. Contaminants of significant concern due to high concentration are inorganic arsenite and petroleum hydrocarbons, such as naphthalene. Parsons Corporation and the Massachusetts Department of Environmental Protection have implemented a bioremediation pilot to attempt to degrade the hydrocarbons and arsenic with the application of nitrate. The nitrate would act as an electron acceptor for biodegradation of the hydrocarbon contaminants, produce nitrite that would oxidize reduced iron, and iron oxides would sequester arsenic. Preliminary data showed …

Environmental Toxicants And Human B Cells: Insights From Crispr Editing And Genomic Sequencing, Clayton Allex-Buckner

Browse all Theses and Dissertations

The human immunoglobulin heavy chain gene locus (IGH) has two 3 prime regulatory regions (3’IGHRR), each containing three enhancers (hs3, hs1.2, hs4). In animal models, the 3’IghRR regulates IgH expression and class switch recombination (CSR) to different Ig isotypes. The 3’IGHRR hs1.2 enhancer in humans is polymorphic in that an invariant sequence (IS) can be repeated one to four times in tandem. The hs1.2 polymorphism is of interest due to its association with several human autoimmune disorders and its potential sensitivity to exogenous substances such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin). In mouse models, TCDD inhibits the hs1.2 enhancer and 3’IghRR …

Clonal Diversity, Antibiotic Resistance, And Virulence Factor Prevalence Of Community Associated Staphylococcus Aureus In Southeastern Virginia, Katelyn D. Cranmer, Mohan D. Pant, Suzanne Quesnel, Julia A. Sharp

EVMS School of Health Professions Faculty Publications

Staphylococcus aureus is a significant human pathogen with a formidable propensity for antibiotic resistance. Worldwide, it is the leading cause of skin and soft tissue infections (SSTI), septic arthritis, osteomyelitis, and infective endocarditis originating from both community- and healthcare associated settings. Although often grouped by methicillin resistance, both methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains are known to cause significant pathologies and injuries. Virulence factors and growing resistance to antibiotics play major roles in the pathogenicity of community-associated strains. In our study, we examined the genetic variability and acquired antibiograms of 122 S. aureus clinical isolates from SSTI, blood, and urinary …

Changes And Relationships Of Soil Aluminum, Organic Matter, And Hydrogen Ion Concentration With Rye Cover Crop, Arron Wilder

Cal Poly Humboldt theses and projects

Soil acidity is a common agricultural problem worldwide, as approximately 50% of all potentially arable soils are affected by pH limitations. At soil pH 3+) is considered to be the chemical form of aluminum in acid soil that hinders plant growth the most. Potentially, soil organic matter (SOM) can ameliorate the toxic effects of Al³⁺ on plants and microbes by binding with Al³⁺, thus preventing Al³⁺ (and other species of aluminum) from interacting in the rhizosphere. Increasing SOM also increases soil health indicators (i.e., microbial activity, soil water holding capacity, aggregate stability, porosity, etc.) while the …

Implications Of Intraspecific Variation In Soil Microbes On Solidago Performance, Yazeed Alshammari

Masters Theses

This study explored the implications of intraspecific variation in soil microbes on the performance of Solidago altissima, a North American species that has become invasive across several continents. This research explored how different clones of Solidago altissima were associated with bacterial and fungal soil microbial communities, which influenced plant performance. In a common garden of 24 Solidago altissima clones, I analyzed the relationship between soil microbial communities, foliar chemistry, clone genetic relatedness, and plant performance. My methods included analysis of soil microbial communities (bacterial and fungal), genetic distances among clones to assess relatedness, and measures of plant performance (light …

The Impact Of Nutrient Depletion On The Effect Of Hhq On Emiliania Huxleyi, Marley Gonsalves

Honors Theses and Capstones

Emiliania huxleyi is a ecologically important, bloom-forming coccolithophore. HHQ is a bacteria compound that causes cell stasis in E. huxleyi that can lead to bloom termination. This study analyzed the role that nutrient depletion plays in this relationship. Results show that nitrogen depletion protects cells from the effects of HHQ, affecting bloom dynamics.

Identification Of Novel Biosynthetic Gene Clusters Encoding For Polyketide/Nrps-Producing Chemotherapeutic Compounds From Marine-Derived Streptomyces Hygroscopicus From A Marine Sanctuary, Hannah Ruth Flaherty

Honors Theses and Capstones

Nearly one out of six deaths in 2020, around ten million people, were caused by cancer, making it a leading cause of death worldwide (WHO, 2022). This major public health issue, in addition to the rise of multidrug-resistant (MDR) pathogens, provides a high demand for the discovery of new pharmaceutical drugs to be used clinically to treat these conditions. The Streptomyces genus accounts to produce 39% of all microbial metabolites currently approved for human health, indicating its potential as an important species to study for antimicrobial and anticancer agents. The long linear genome of Streptomyces contains specialized sequences known as …

Investigating The Impact Of Nonenzymatic Lysine Acetylation On The Function Of The Bacterial Ribosome, Sarah Caldwell Feid

Dissertations

An under-investigated target of lysine acetylation is the bacterial ribosome. Although lysine acetylations on the ribosome are common and conversed in diverse bacterial species, little work has been done to understand how lysine acetylation affects the bacterial ribosome. The goal of this work is to determine if lysine acetylation has functional impact on the bacterial ribosome.I have identified in vitro and in vivo effects of nonenzymatic, AcP-dependent lysine acetylation on translation and the ribosome. In vitro acetylation of transcription-translation reactions causes a translation-specific defect that is unaffected by the addition of the CobB deacetylase. This suggests certain AcP-sensitive residues that …

Metabolic Engineering Of Escherichia Coli For N-Acetyl-Glucosamine Production, Anica Tasnim Protity

Graduate Research Theses & Dissertations

Glucosamine (GlcN) and GlcN-based supplements, such as N-acetyl-glucosamine (GlcNAc), are commonly used by osteoarthritis patients to relieve pain and maintain the health of bone joints. However, the current production methods for GlcN-based products are not eco-friendly and pose risks to individuals with shrimp allergies. Microbial cell-based systems have been explored to address these issues as an eco-friendly alternative for GlcN and GlcNAc production. This study focused on developing an Escherichia coli (E. coli) strain for GlcNAc fermentation. E. coli has an endogenous pathway for peptidoglycan biosynthesis involving GlcNAc-1-P. However, altering this pathway could affect cell growth and integrity. Therefore, two …

Pancreatic Ductal Adenocarcinoma And New Treatments In Development, Melissa J. Moisan

Biology and Microbiology Graduate Students Plan B Research Projects

Pancreatic ductal adenocarcinoma (PDAC) is the most frequently mutated (95%) 5exocrine pancreatic cancers. Patients with PDAC are also the least likely to survive more than 5 years with only 8% overall survivability. The median survival for patients with distant metastasis is less than one year. Most pancreatic ductal adenocarcinoma occurs in the pancreatic head, and the remainder can be found within the body (5% to 15%) or tail (10% to 15%) (14). This extremely aggressive cancer has an increasingly large metastatic dissemination rate to surrounding organs such as the liver, lung, and peritoneum, or can be seen as distant metastases …

Investigating The Impacts Of Ammonium Phosphate-Based Fire Retardants On Cyanobacteria (Anabaena) Growth, Gavin Sutter, Brenda Gonzalez Flores, Grace Laskey, Shane Jurak

Humboldt Journal of Microbiology

In recent years the effects of climate change have taken a devastating toll on ecosystems around the world. With high temperatures and extreme droughts, wildfires have become increasingly common. In order to combat these natural disasters wildland firefighters, drop millions of gallons of fire retardant on public lands and forests. These fire retardants consist of between 80%-100% ammonium phosphate which are incredibly effective as fire suppressants yet is more commonly known for its use in fertilizer. Ammonium phosphate fertilizers can lead to stream eutrophication and undesirable environmental impacts. Our research aims to address the effects of fire retardant on growth …