Microbiology Commons^™

Straw Cover Increases Garden Soil Microbial Biodiversity, Emory Walker, Mara Welty, Emma Creviston

The Journal of Purdue Undergraduate Research

No abstract provided.

A Comparison Of White-Light And Monochromatic Led Sources For Antimicrobial Photodynamic Inactivation Of Staphylococcus Aureus, Emily Simmons

The Journal of Purdue Undergraduate Research

Drug-resistant bacteria are an ongoing public health crisis for which alternative treatments are needed. One alternative is antimicrobial photodynamic inactivation (aPDI), which uses potent photosensitizers and light irradiation to damage the bacteria. Our standard light source used in aPDI is a single-wavelength light source at 405-nm; however, we evaluated a white-light source for similarities in the resulting aPDI activities. This is done by comparing aPDI experiments using S. aureus and its methicillin-resistant strains (MRSA) conducted with either the white LED light source or the 405-nm LED light source. Statistical analysis using t-tests revealed no significant differences in the aPDI activities …

Development Of Broadly Protective Vaccines Against New World Arenaviruses, Brian B. Gowen

Funded Research Records

No abstract provided.

Role Of Cellular Stress Responses In Innate Immune Defense Against Acute Respiratory Infections, Amit Sharma

LSU Doctoral Dissertations

The endoplasmic reticulum (ER) stress sensor inositol-requiring enzyme 1α (IRE1α) is an important regulator of innate immune cells. However, its role in pulmonary innate host defenses remains poorly understood. This dissertation elucidates the dual, context-dependent role of IRE1α in host defense against methicillin-resistant Staphylococcus aureus (MRSA) pneumonia. We demonstrate IRE1α’s function as both a detrimental mediator of acute pathology and an essential facilitator of innate immune memory. Our work revealed that acute IRE1α activation during primary MRSA infection is detrimental. In lungs and alveolar macrophages (AMs), IRE1α is activated in response to MRSA infection. Consequently, IRE1α activation triggers a hyperinflammatory …

Microplastic Exposure Alters Tubulin Leading To Alterations In Insulin Secretion By Pancreatic Beta Cells, Anakaren Garcia

Honors Program Theses and Research Projects

Abstract

Diabetes mellitus is a metabolic disorder characterized by elevated blood glucose levels due to impaired insulin secretion or diminished cellular response to insulin (resistance). Pancreatic β-cells depend on a well-organized cytoskeleton, particularly microtubules composed of α- and β-tubulin heterodimers, to transport insulin granules to the plasma membrane during glucose-stimulated insulin secretion (GSIS). Disruption of microtubule organization can impair granule trafficking and reduce insulin release. However, emerging environmental toxicants such as microplastics that interfere with β-cell cytoskeletal function remains largely unexplored.

Microplastics (MPs) are small plastic particles (< 5 mm) that have become widespread environmental contaminants and can enter biological systems. Previous studies have shown that MPs can induce cellular stress and protein misfolding, but their effects on microtubules in pancreatic β-cells are not well characterized. This study investigates whether exposure to fluorescent polystyrene microplastics alters microtubule organization and insulin secretion in βTC-6 cells.

βTC-6 cells were treated with 10 µg/mL of fluorescent polystyrene microplastics for …

Exploring The Role Of Faecalibacterium Prausnitzii Metabolites In Modulating Fatty Acid Metabolism And Protecting Hepg2 Cells During Induced Steatosis, Morgan Martin, Emerald Cole

Student Scholar Symposium

The obesity epidemic has risen to astronomical numbers with over 650 million adults being classified as obese (BMI≥30). Obesity is of critical concern as excess body fat storage is a comorbidity to various diseases including type-2 diabetes, cardiovascular disease, and cancer. Although obesity has classically been attributed to genetics and unhealthy lifestyle choices, there is a growing interest in other factors affecting obesity, including the gut microbiome. For example, mice lacking a microbiome are resistant to weight gain even when placed on a high-calorie diet. It can then be concluded that bacteria and the metabolites they produce can dramatically affect …

Advancing Louisiana's Cropping Systems: Sustainable Bioenergy Production, Cover Crops, And Technology Integration, Pedro R. Carrillo

LSU Doctoral Dissertations

The adoption of cover crops in Louisiana is lower than the national average, underscoring the need for region-specific research to address environmental challenges and demonstrate the short-term benefits of these practices within existing production systems. This research evaluated the integration of cover crops (CC) in energy cane (Saccharum spp.) and no-till cotton systems, focusing on their effects on soil health, nitrogen (N) management, and biomass production. Soil health indicators (SHIs), including enzymatic activities (β-glucosidase, β-glucosaminidase, and urease), protein N, inorganic N concentrations (nitrate and ammonium), soil organic matter (SOM), and microbial community composition assessed through ester-linked fatty acid …

Ecology Of Subaerial Algae: Photosynthetic Capacity As A Function Of Relative Humidity In A Naturally- Occurring Association, James A. Nienow

Georgia Journal of Science

Subaerial algae are defined by their ability to grow on surfaces exposed directly to the air. We are currently investigating the nature of the adaptations that allow these unicellular microorganisms to form rich growths in an environment subjected to repeated and prolonged periods without liquid water. It is well known from laboratory studies that at least some members of the group are able to sustain metabolic activity using water vapor at high relative humidity. However, data concerning the significance of this ability in natural populations are almost completely lacking. To help fill in this gap, we tracked the photosynthetic capacity …

The Triangular Interaction Between Dietary Polyphenols, Gut Microbiota, And Metabolic Syndrome, Emily Bayliss

Senior Honors Theses

Type 2 diabetes mellitus (T2DM) is a growing global health concern characterized by peripheral insulin resistance as well as impaired insulin secretion from pancreatic β-cells. Emerging evidence suggests that the gut microbiome, specifically gut dysbiosis, an imbalance in the gut microbiome, is a critical modulator of the pathophysiology of T2DM. Dietary polyphenols, a diverse group of bioactive compounds that are abundant in plant-based foods, have recently gained attention for their potential to attenuate metabolic disorders through their antioxidant and anti-inflammatory properties as well as through modulating the composition and activity of gut microbes, thereby attenuating dysbiosis. However, the diabetic state …

Twim #243: Beef And Bacillus, Sakiem Winston, Madison Wolford, Rebecca Seipelt-Thiemann, Angela Wilson

School of Medical Diagnostics & Translational Sciences Publications

Podcast annotation TWiM #243: Beef and Bacillus from the weekly podcast series "This Week in Microbiology" (TWiM), a podcast where experts in microbiology discuss academic papers in their field in an informal way.

Twim #261: Overwhelming Microbial Greatness, Jenny Stoval, Briana Lanzarotta, Luke Boseman, Nicole L. Podnecky, Angela Wilson

School of Medical Diagnostics & Translational Sciences Publications

Podcast annotation TWiM #261: Overwhelming Microbial Greatness from the weekly podcast series "This Week in Microbiology" (TWiM), a podcast where experts in microbiology discuss academic papers in their field in an informal way.

Twim #286: Integrons And Invasion, Andrea Ayala-Lopez, Brittney Heist,, Thomas Salazar, Rebecca Seipelt-Thiemann, Mel Melendrez-Vallard, Angela Wilson

School of Medical Diagnostics & Translational Sciences Publications

Podcast annotation TWiM #286: Integrons and Invasion from the weekly podcast series "This Week in Microbiology" (TWiM), a podcast where experts in microbiology discuss academic papers in their field in an informal way.

Twim #222: Biosensors In Bacteria, Madison Hayes, Alexis Austin, Dillon Nguyen, Angela Wilson, Rebecca Seipelt-Thiemann

School of Medical Diagnostics & Translational Sciences Publications

Podcast annotation TWiM #222: Biosensors in Bacteria from the weekly podcast series "This Week in Microbiology" (TWiM), a podcast where experts in microbiology discuss academic papers in their field in an informal way.

Advancing The Virus Diagnostic Toolkit: Development Of Accurate And Reliable Artificial Virus-Mimicking Positive Controls And Crispr-Based Detection, Habeeb Yinka Atanda

Graduate Theses and Dissertations

Accurate and reliable detection of plant viruses is critical for protecting berries and other economically important crops. Yet diagnostic programs face persistent challenges with positive control availability, biosafety concerns, and specificity limitations. This thesis advances the diagnostic toolkit for berry viruses through three complementary innovations that address fundamental gaps in current detection methodologies. First, this research developed and validated virus-mimicking artificial positive controls (ViMAPCs) for diverse viruses affecting berry crops for endpoint PCR applications. ViMAPCs incorporate size differentiation, which enables immediate visual gel band discrimination between control and natural infection signals. Amplification efficiency analysis demonstrated close correspondence with true-positive controls …

Fungal Biodiversity, Microbial Communities, And Ecosystem Function In Non-Perennial Streams, Charles T. Bond

Dissertations

A global majority of steams are non-perennial, drying at some point in time and space. Despite the vital roles that fungi and other microbes play in stream ecosystems, most research on stream microbiomes comes from perennial (continuously flowing) streams. The present series of studies addresses this research gap by examining microbial community composition and function in non-perennial streams, with an emphasis on fungi. Chapter I reviews existing scientific literature on the ecological processes that shape microbiome structure and function in non-perennial streams and outlines the varieties of fungi that may live there. Chapter II uses rDNA metabarcoding to survey fungal …

Structure And Function Studies On Trna Splicing Endonuclease, Justin G. Underwood

Dissertations and Theses (Open Access)

A subset of eukaryotic pre-tRNAs have introns that must be spliced out to become mature molecules capable of functioning in translation. This essential processing step is performed by tRNA splicing endonuclease (TSEN), a highly conserved heterotetramer with two catalytic and two structural subunits. In addition to this conserved function, archaeal TSEN also processes pre-rRNA and yeast TSEN cleaves some mRNAs that encode mitochondrial proteins to initiate mRNA degradation. Interestingly, single amino acid mutations in TSEN cause the human Mendelian disease pontocerebellar hypoplasia (PCH) by an unknown mechanism. Recently, several groups have determined the structure of human TSEN, revealing similarities and …

Tracing The Journey Of Dissolved Organic Matter: From Leaf Litter Photodegradation To Microbial Processing In Tropical Streams, Samantha Nicole Sullivan

Chemistry & Biochemistry Theses & Dissertations

Dissolved organic matter (DOM) is a major reservoir of organic carbon in aquatic ecosystems and plays a central role in global carbon cycling through its transformation and remineralization to carbon dioxide (CO₂). As DOM moves from terrestrial environments into streams and rivers, its chemical composition is altered by a combination of microbial and photochemical oxidation processes that regulate both its reactivity and its persistence during transport. However, the molecular mechanisms governing these oxidative transitions, particularly in tropical ecosystems characterized by strong hydrologic seasonality and substantial inputs of plant-derived material, remain insufficiently resolved. This dissertation integrates ultrahigh-resolution mass spectrometry, optical characterization, …

Investigating The Impacts Of Azole Antifungals On Growth Of Cryptococcus Neoformans, Gnanambika Sindhe

All Theses

Cryptococcus neoformans, an opportunistic fungal pathogen is responsible for cryptococcosis, leading to approximately 181,000 deaths annually, predominantly in regions such as Sub-Saharan Africa. Fluconazole, a widely used fungistatic azole, is often administered due to its relative affordability and lower toxicity. However, resistance to fluconazole in C. neoformans can arise through aneuploidy, complicating treatment efforts. This study aims to deepen our understanding of resistance mechanisms to azole drugs by comparing fluconazole with other azoles, including both clinical and agricultural azole antifungals. Disk diffusion assays were performed to evaluate the ability of C. neoformans to develop resistance to these compounds, focusing …

Requirement Of Prepiilin Peptidase Activity For Variovorax Paradoxus Eps Flp/Fap Pilus Assembly, Jenny L. Lanthripp

Electronic Theses, Projects, and Dissertations

Variovorax paradoxus is a Gram-negative aerobic bacterium present in both soil and the human oral microbiome. This species contributes to biotransformation of xenobiotics and promotes plant growth. Interestingly, although the genome of strain EPS lacks the flagellum operon annotated in strain S110, the microbe remains motile, and flagella can be observed microscopically. To investigate this unexpected phenotype, motility mutants were enriched from a Tn5 mutant library using a liquid culture settling strategy. A total of 122 isolates were screened for motility defects, and 57 exhibited significantly reduced motility compared to the wild type. Rescue cloning revealed that over 60% of …

The Microstructure Of Metastatic Bone Lesions Suggests Tumor Mediated Alterations In Bone Mineralization, Hanwen Fan, Zhan Xu, Carla Berrospe Rodriguez, Noah Dover, Andrei Demkov, Morgan Lilly, Guillermo Aguilar, Larry J Suva, Xiang H-F Zhang, Yuxiao Zhou

Faculty, Staff and Students Publications

Breast, prostate and lung cancer cells frequently metastasize to bone, leading to disruption of the bone microstructure. This study utilized mechanical testing coupled with micro-CT imaging, digital volume correlation (DVC), and atomic force microscopy (AFM) nanomechanical testing to examine the mechanical property variations in mouse long bones (tibia) with metastatic lung cancer cell involvement, spanning from the whole-bone scale to the microstructural level. In addition, we also investigated how metastatic invasion alters the morphology of hydroxyapatite nanocrystals in bone at the nanometer scale. The biochemical composition within metastatic lesions was assessed using Raman spectroscopy and correlated with AFM mechanical testing …