Microbiology Commons^™

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 #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.

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 …

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 …

Functional Analysis Of Ftsa-Mediated Recruitment Of Ftsk In Escherichia Coli, Abbigale Perkins

Dissertations and Theses (Open Access)

Bacterial cytokinesis requires precise coordination between cytoplasmic and periplasmic components of the divisome to ensure that membrane constriction and chromosome segregation occur in synchrony. The actin-like protein FtsA plays a central role in this process by tethering FtsZ to the membrane and recruiting downstream division proteins. Despite its essential function, the mechanisms by which FtsA coordinates divisome activation and the recruitment of late-acting proteins remain incompletely defined. To address this, the role of FtsA in activating septal synthesis and recruiting the DNA translocase FtsK was examined using mutational analysis in Escherichia coli.

The FtsA^{M96E R153D} variant, which has …

Strategic Enhancement Of Biofuel Production Using Bacillus Subtilis As A Model Organism: A Dual Approach Of Gene Essentiality Mapping And Optimization, Angela A. Zebede

Electronic Theses and Dissertations

With rising global demand for renewable energy, enhancing microbial platforms for biofuel production is vital. This study engineered Bacillus subtilis to improve resilience to solvent stress by targeting membrane lipid biosynthesis pathways essential for integrity. Growth curve analysis (OD₆₀₀) showed that phosphatidylserine (PS) and phosphatidylethanolamine (PE) knockout strains grew significantly slower than wild type (168), indicating the importance of these lipids under stress. Laurdan fluorescence spectroscopy was used to assess membrane properties. Generalized polarization (GP) analysis revealed a concentration-dependent reduction in membrane order upon 1%–2% 1-butanol exposure. GP values declined progressively from control to 2% treatment, reflecting increased membrane fluidity …

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.

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 #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.

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 …

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, …

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 …

Lilrb4 Regulates Circadian Disruption-Induced Mammary Tumorigenesis Via Non-Canonical Wnt Signaling Pathway, Olajumoke Ogunlusi, Mrinmoy Sarkar, Kayla Carter, Arhit Chakrabarti, Devon J Boland, Tristan Nguyen, James Sampson, Christian Nguyen, Danielle Fails, Yava Jones-Hall, Loning Fu, Gus Wright, Da Mi Kim, James J Cai, Bani Mallick, Alex C Keene, Jeff R Jones, Tapasree Roy Sarkar

Faculty, Staff and Students Publications

Epidemiological studies have shown that circadian rhythm disruption (CRD) is associated with the risk of breast cancer. However, the role of CRD in mammary gland morphology and aggressive basal mammary tumorigenesis and the molecular mechanism underlying CRD-induced carcinogenesis remain unknown. To investigate the effect of CRD on aggressive tumorigenesis, a genetically engineered mouse model of aggressive breast cancer was used. The impact of CRD on the tumor microenvironment was investigated using the tumors from LD12:12 and CRD mice via scRNA-seq, flow cytometry, multiplexing immunostaining, and realtime PCR. The effect of LILRB4-immunotherapy on CRD-induced tumorigenesis was also investigated. Here we investigated …

Nivolumab Plus Ipilimumab Induce Hyper-Progression In Renal Medullary Carcinoma: Results Of A Phase Ii Trial And Preclinical Evidence, Melinda Soeung, Xinmiao Yan, Ciro Zanca, Jing Qian, Menuka Karki, Fei Duan, Hania Khan, Li Zhang, David H Peng, Mariah Williams, Rong He, Ziheng Chen, Luigi Perelli, Jianfeng Chen, Rebecca S Tidwell, Pankaj K Chauhan, Courtney N Le, Truong N A Lam, Nirjar Bhattacharya, Rutvi Shah, I-Lin Ho, Jason P Gay, Caroline C Carrillo, Ningping Feng, Kang Le, Guang Gao, Teresa L Perry, Faika Mseeh, Yongying Jiang, Quanyun A Xu, Niki Marie Zacharias, Rahul A Sheth, Tharakeswara K Bathala, Priya Rao, Najat C Daw, Durga N Tripathi, Cheryl L Walker, Mohammad M Mohammad, Jianhua Zhang, Guangchun Han, Yanshuo Chu, Ruiping Wang, Minghao Dang, Enyu Dai, Fuduan Peng, Yunhe Liu, Akshaya Jadhav, Wenhua Lang, Claudio A Arrechedera, Leticia Campos Clemente, Edwin R Parra, Hsinyi Lu, Cara L Haymaker, Ignacio I Wistuba, Andrew Futreal, Andrea Viale, Michael J Soth, Philip Jones, Joseph R Marszalek, Timothy Heffernan, Giulio F Draetta, Nizar M Tannir, Jianjun Gao, Linghua Wang, Giannicola Genovese, Pavlos Msaouel

Faculty, Staff and Students Publications

Therapeutic options for patients with renal medullary carcinoma (RMC) are limited. Here we report the results of a phase II clinical trial (NCT03274258) of anti-PD1 nivolumab plus anti-CTLA4 ipilimumab in patients with RMC, with objective response rate as primary outcome. Enrollment was halted for futility at a prespecified interim analysis as all 10 treated patients experienced rapid disease progression. 5/10 met radiological criteria for hyperprogression and median progression-free survival (secondary outcome) was 1.38 months (95% confidence interval: 1.28, 1.60). In a post-hoc single-cell RNA sequencing analysis, data from patients with RMC before and after nivolumab plus ipilimumab treatment indicated that …

Antifungal Effects Of Fatty Acids On The Growth Of Ophidiomyces Ophiodiicola In A Simulated Snake Skin Environment, Krupa S. Patel, Lizbeth Delarosa, Jacey Cardenas, Thalia Rodriguez, John Niedzwiecki

Science University Research Symposium (SURS)

Emerging infectious diseases have increasingly threatened wildlife populations worldwide, with devastating impacts observed in frogs, bats, and more recently, snakes. Snake fungal disease (SFD), caused by the pathogenic fungus Ophidiomyces ophiodiicola (Oo), currently poses a serious threat to snake populations across multiple regions. Infected snakes exhibit disrupted skin shedding, rough or scaly patches, crusty sores, and ulcers that compromise their health and survival. Although the mechanisms underlying transmission and susceptibility to SFD remain unclear, the snake cutaneous microbiome is known to act as a defensive barrier, mediating interactions between the host and invading pathogens. The lipid layer is a key …