Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Bacteriology (114)
- Environmental Microbiology and Microbial Ecology (76)
- Medicine and Health Sciences (58)
- Pathogenic Microbiology (53)
- Biology (46)
-
- Biochemistry, Biophysics, and Structural Biology (45)
- Genetics and Genomics (32)
- Molecular Biology (25)
- Other Microbiology (25)
- Diseases (24)
- Organisms (24)
- Medical Sciences (23)
- Bacteria (22)
- Biochemistry (22)
- Organismal Biological Physiology (22)
- Cell and Developmental Biology (17)
- Medical Microbiology (17)
- Bacterial Infections and Mycoses (15)
- Molecular Genetics (15)
- Immunology and Infectious Disease (12)
- Bioinformatics (11)
- Biotechnology (11)
- Cell Biology (11)
- Ecology and Evolutionary Biology (11)
- Food Science (11)
- Genetics (11)
- Physical Sciences and Mathematics (11)
- Institution
-
- Eastern Illinois University (22)
- University of Nebraska - Lincoln (18)
- University of Arkansas, Fayetteville (13)
- Dartmouth College (10)
- The Texas Medical Center Library (10)
-
- Virginia Commonwealth University (10)
- East Tennessee State University (8)
- University of Kentucky (8)
- City University of New York (CUNY) (7)
- California Polytechnic State University, San Luis Obispo (6)
- Munster Technological University (6)
- Washington University in St. Louis (6)
- University of Nevada, Las Vegas (5)
- Montclair State University (4)
- Universitas Indonesia (4)
- Nova Southeastern University (3)
- Old Dominion University (3)
- The University of Southern Mississippi (3)
- University of Nebraska Medical Center (3)
- University of Texas at Arlington (3)
- Bridgewater College (2)
- Claremont Colleges (2)
- Eastern Washington University (2)
- Portland State University (2)
- South Dakota State University (2)
- The University of Akron (2)
- University of Central Florida (2)
- University of Louisville (2)
- University of South Florida (2)
- University of Tennessee at Chattanooga (2)
- Keyword
-
- Microbiology (11)
- Bacteria (9)
- Acetogenesis (7)
- Biofilm (7)
- Acetyl-CoA pathway (6)
-
- Escherichia coli (6)
- Gene regulation (6)
- Gut microbiome (6)
- Metabolism (6)
- Microbiome (6)
- Moorella thermoacetica (6)
- Oxalate (6)
- PH (6)
- Acidification (5)
- Candida albicans (5)
- Mycobacteria (5)
- Regulation (5)
- 1.6 BIOLOGICAL SCIENCES (4)
- Acetogenic bacteria (4)
- Antibiotic Resistance (4)
- Antibiotic resistance (4)
- Antifungal (4)
- Autotrophy (4)
- Bioenergetics (4)
- Biology (4)
- Electron transport (4)
- Gene expression (4)
- Genetics (4)
- Nitrate dissimilation (4)
- Peptidoglycan (4)
- Publication Year
- Publication
-
- Faculty Research & Creative Activity (21)
- Dissertations and Theses (Open Access) (10)
- Electronic Theses and Dissertations (8)
- Theses and Dissertations (8)
- Graduate Theses and Dissertations (7)
-
- Biology Faculty Research (6)
- Dartmouth Scholarship (6)
- Biological Sciences Undergraduate Honors Theses (5)
- Department of Biological Sciences Publications (5)
- Department of Food Science and Technology: Faculty Publications (5)
- Master's Theses (5)
- Dartmouth College Ph.D Dissertations (4)
- Department of Biology Faculty Scholarship and Creative Works (4)
- Dissertations, Theses, and Capstone Projects (4)
- Honors Theses (4)
- Makara Journal of Science (4)
- School of Biological Sciences: Dissertations, Theses, and Student Research (4)
- Theses and Dissertations--Microbiology, Immunology, and Molecular Genetics (4)
- Biology Faculty Scholarship (3)
- Department of Food Science and Technology: Dissertations, Theses, and Student Research (3)
- Dissertations (3)
- Dissertations and Theses (3)
- Theses & Dissertations (3)
- Undergraduate Honors Theses (3)
- All HCAS Student Capstones, Theses, and Dissertations (2)
- Biological Sciences Theses & Dissertations (2)
- Biology Dissertations - Archive (2)
- EWU Masters Thesis Collection (2)
- Graduate Theses, Dissertations, and Problem Reports (ETD) (2)
- Honors Program: Senior Projects (Public) (2)
- Publication Type
- File Type
Articles 1 - 30 of 221
Full-Text Articles in Microbial Physiology
Antimicrobial Responses Of Staphylococcus Aureus In Simulated Spaceflight Conditions, Mikayla Dutkiewicz, Yegor Bushnev
Antimicrobial Responses Of Staphylococcus Aureus In Simulated Spaceflight Conditions, Mikayla Dutkiewicz, Yegor Bushnev
Discovery Day - Daytona Beach
Microbial persistence in confined environments, such as spacecraft, can pose challenges to astronaut health and habitat maintenance. This project investigates Staphylococcus aureus, a Gram-positive bacterium commonly associated with human microbiota and opportunistic infections, in spaceflight-relevant environmental conditions. Further, this project will assess the influence of the antimicrobial/antioxidant compound quercetin to assess its effects on bacterial growth and virulence under standard Earth gravity and simulated International Space Station (ISS) conditions. This approach will assess whether spaceflight-relevant stressors, including microgravity and radiation, alter treatment efficacy by influencing microbial physiology and antimicrobial susceptibility. Data collection and analysis are ongoing, and results are expected …
Imidacloprid Effects On The Survival And Cutaneous Microbiome Of Northern Leopard Frogs, Evelyn Margaret Osterloo
Imidacloprid Effects On The Survival And Cutaneous Microbiome Of Northern Leopard Frogs, Evelyn Margaret Osterloo
Honors Thesis
Amphibians are experiencing population declines due to habitat loss, climate change, and diseases, particularly chytridiomycosis caused by the fungus Batrachochytrium dendrobatidis. Protection from this fungal infection stems from the cutaneous microbiome. Pesticides have been shown to affect amphibians in a variety of ways, including reducing survival, locomotor performance, and accumulation in body tissues. Pesticides may also lead to changes in the cutaneous microbiome affecting amphibians who rely on these organisms as an anti-Bd defense mechanism. To investigate the effect of imidacloprid, a neonicotinoid insecticide, Northern Leopard frogs (Lithobates pipiens) were subjected to sublethal concentrations (control = …
Effect Of Novel Antimicrobial Compounds On Fungal And Bacterial Pathogens, Megan Wilderman
Effect Of Novel Antimicrobial Compounds On Fungal And Bacterial Pathogens, Megan Wilderman
Honors Program: Senior Projects (Public)
Antimicrobial resistance is a growing concern in medicine1 leading to a need for the development of novel compounds. Two compounds were tested in this study, 2-hydroxyethylhydrazine (HEH) and para-nitrophenyl-isocyanide (NPIC). HEH targets phosphatidylcholine (PC) production2, and NPIC targets mitochondrial function3. Choline (Cho) is a compound that bypasses the inhibition of HEH through the Kennedy pathway.2 Two-fold serial dilutions were conducted in 96-well plates to test the sensitivity of different bacteria to HEH and fungi to HEH and NPIC in different media types. A choline condition was also included in the HEH dilutions to test …
Investigating Corollaries Between Streptococcus Gallolyticus Subsp. Gallolyticus Virulence And Colorectal Cancer, Tyler G. Myers
Investigating Corollaries Between Streptococcus Gallolyticus Subsp. Gallolyticus Virulence And Colorectal Cancer, Tyler G. Myers
Pursuit - The Journal of Undergraduate Research at The University of Tennessee
Streptococcus gallolyticus subsp. gallolyticus (Sgg) is a gram-positive, non-beta-hemolytic bacterium that belongs to the Lancefield group D of streptococcal pathogens. For the past several decades, associations between Sgg bacteremia and colorectal cancer (CRC) have been apparent, with gastroenterologists routinely recommending colonoscopies for positive cases of Sgg in either blood or stool samples. However, current research has not wholly established whether Sgg acts as a causative agent of CRC or if pre-existing cancers make the lumen of the colon more hospitable to its colonization. Regardless, Sgg has been implicated in the modulation of host inflammatory pathways and subsequent remodeling …
Modulating Oran Nitrate-Reducing Bacteria To Enhance Nitric Oxide Bioavailability As A Therapeutic Target For Atherosclerosis, Donovan C. Davidson
Modulating Oran Nitrate-Reducing Bacteria To Enhance Nitric Oxide Bioavailability As A Therapeutic Target For Atherosclerosis, Donovan C. Davidson
CMC Senior Theses
Atherosclerosis remains the primary driver of global cardiovascular disease, yet clinical interventions are largely restricted to high-cost, invasive procedures only after it has reached a critical stage. Recent research has identified a connection between the oral microbiome and vascular health via the enterosalivary nitrate-nitrite-nitic oxide (NO) pathway. Oral nitrate-reducing bacteria (ONRB) drive the synthesization of NO by reducing dietary nitrate into nitrite, which is then converted into bioavailable NO. NO is a potent vasodilator that maintains endothelial health by suppressing inflammation through inhibiting the expression of adhesion molecules VCAM-1 and ICAM-1. However, this pathway is easily compromised by dysbiotic oral …
Repurposing Cyclin-Dependent Kinase Inhibitors For The Discovery Of Novel Antiplasmodial Compounds, Ritam Bhowmik
Repurposing Cyclin-Dependent Kinase Inhibitors For The Discovery Of Novel Antiplasmodial Compounds, Ritam Bhowmik
Honors Undergraduate Theses
Malaria remains a major global health burden with over 282 million cases annually and rising resistance to artemisinin-based combination therapies. Plasmodium falciparum, the most lethal malaria parasite species in humans, relies on tightly regulated cell cycle progression during replication within red blood cells. Cyclin-dependent kinases (CDKs) are central regulators of eukaryotic cell division and transcription, and several CDK-like enzymes in P. falciparum, including Pfmrk and PfPK6, are essential for parasite growth and structurally distinct from human kinases. This study evaluated whether commercially available human CDK inhibitors (CDKIs) targeting cancer pathways could be repurposed as novel antimalarial compounds. A library of …
Coordinating The Layers: Regulation Of Peptidoglycan Synthesis And Cell Wall Assembly In Mycobacterium Smegmatis By Murj And Pgfa, Karen Emmanuella Samaga-De-Tembiwa
Coordinating The Layers: Regulation Of Peptidoglycan Synthesis And Cell Wall Assembly In Mycobacterium Smegmatis By Murj And Pgfa, Karen Emmanuella Samaga-De-Tembiwa
Biology Dissertations
The mycobacterial cell envelope consists of three covalently linked layers whose synthesis must be coordinated to maintain structural integrity during polar growth. While the biosynthetic enzymes for each layer are well characterized, the molecular mechanisms that coordinate synthesis across layers have remained poorly understood. This thesis investigates two essential transmembrane proteins, PgfA and MurJ, that regulate peptidoglycan metabolism in Mycobacterium smegmatis and provide new insight into how mycobacteria synchronize cell wall assembly.
We present evidence that PgfA functions as a bifunctional regulator that links peptidoglycan metabolism to the availability of trehalose monomycolate (TMM), a key mycolic acid precursor. Through epistasis …
Exploring The Role Of Faecalibacterium Prausnitzii Metabolites In Modulating Fatty Acid Metabolism And Protecting Hepg2 Cells During Induced Steatosis, Morgan Martin, Emerald Cole
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 …
Requirement Of Prepiilin Peptidase Activity For Variovorax Paradoxus Eps Flp/Fap Pilus Assembly, Jenny L. Lanthripp
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 …
Investigating The Mechanisms Of Microbial Interactions Using A Model Cystic Fibrosis Polymicrobial Community, Bassam El Hafi
Investigating The Mechanisms Of Microbial Interactions Using A Model Cystic Fibrosis Polymicrobial Community, Bassam El Hafi
Dartmouth College Ph.D Dissertations
Cystic fibrosis (CF) airway microbial communities are complex ecosystems where interspecies interactions influence pathogen survival and disease progression. We leverage a CF-relevant in vitro four-species model composed of Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus sanguinis, and Prevotella melaninogenica, alongside a microbiome dataset with over 4,000 respiratory samples from publicly available sequencing data of CF patient samples, to explore the dynamics of microbial interactions in CF. On a broader scale, we performed microbial network analysis to examine how the latest modulator therapy, elexacaftor/tezacaftor/ivacaftor (ETI), might influence CF microbial communities. Our analysis revealed a reduction in node connections and …
Effect Of Red And Blue Light On Lipid, Protein, Carbohydrate, And Pigment Contents Of Navicula Sp., Sofyan Maulana, Aulia Setyo Nurul Hida, Ismia Wulandari, Siti Mudrikah, Dedy Kurnianto, Khusnul Qonita Maghfiroh, Ria Amelia, Tia Erfianti, Renata Adaranyssa Egistha Putri, Irika Devi Anggraini, Septhian Marno, Eko Agus Agus Suyono
Effect Of Red And Blue Light On Lipid, Protein, Carbohydrate, And Pigment Contents Of Navicula Sp., Sofyan Maulana, Aulia Setyo Nurul Hida, Ismia Wulandari, Siti Mudrikah, Dedy Kurnianto, Khusnul Qonita Maghfiroh, Ria Amelia, Tia Erfianti, Renata Adaranyssa Egistha Putri, Irika Devi Anggraini, Septhian Marno, Eko Agus Agus Suyono
Makara Journal of Science
Light quality critically modulates the physiology of diatoms, influencing photosynthetic efficiency and metabolite synthesis. This study examines how monochromatic red (620–750 nm) or blue (450–495 nm) light affects the biochemical profiles and pigment production in Navicula sp. versus white light (control). Cultures were grown in sterile f/2 medium, and biomass was tracked via OD680. Biochemical analyses included lipids (Bligh and Dyer method), carbohydrates (phenol-sulfuric acid assay), proteins (Bradford assay), and pigments (spectrophotometric quantification). The growth dynamics were modeled using logistic and Gompertz equations. No significant differences in OD-based growth rates, carbohydrates, proteins, or lipids content were observed with …
Host, Microbiome, And Parasite: How Apicomplexan Microorganisms Interact With Gut Microbiota, Senia Bu, Andrew T. Ozga
Host, Microbiome, And Parasite: How Apicomplexan Microorganisms Interact With Gut Microbiota, Senia Bu, Andrew T. Ozga
Mako: NSU Undergraduate Student Journal
The gut microbiome, a complex ecosystem of microorganisms residing in the human gastrointestinal tract, plays a crucial role in maintaining overall health. It functions in immune system regulation, digestion, and protection against pathogens. Apicomplexan parasites, such as Toxoplasma gondii, Plasmodium spp., and Cryptosporidium spp., are major pathogens that can significantly disrupt the gut microbiota, leading to alterations in microbial composition and function. This review explores the bidirectional interactions between Apicomplexan parasites and the gut microbiome, focusing on how these parasites influence microbial diversity, immune responses, and host metabolism. It examines the mechanisms by which infection-induced inflammation, altered …
Long-Chain Fatty Acids Promote Candida Albicans Gut Colonization By Restructuring The Fungal Cell Surface, Musfirat Shubaita
Long-Chain Fatty Acids Promote Candida Albicans Gut Colonization By Restructuring The Fungal Cell Surface, Musfirat Shubaita
Dissertations and Theses (Open Access)
Long-chain fatty acids promote Candida albicans gut colonization by restructuring the fungal cell surface
Musfirat Shubaita, BS
Advisory Professor: J. Christian Perez, Ph.D.
The yeast Candida albicans is a facultative anaerobe residing in the human digestive tract. Although fungal genetic determinants of mammalian host colonization have been identified, little is known about signals and molecules in the intestinal environment that influence C. albicans proliferation. Previously unpublished data from the Perez lab showed that oleic acid, one of the most abundant long-chain fatty acids in nature, promotes C. albicans colonization of the murine intestine. The goal of this research is to …
Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore
Impact Of Shear Flow On Marine Biofilms Using Hyperspectral Imaging, Shantanu Mahesh Kore
All Theses
Various microbial communities in marine biofilms cause biofouling on submerged surfaces, posing challenges to marine industries. Despite their ecological and economic importance, biofilms' biomechanical and biochemical responses to hydrodynamic shear stress are insufficiently understood, particularly in dynamic flow conditions. To fill this gap, our study uses an innovative fiber-optic hyperspectral imaging (HSI) system and a supercontinuum laser source to examine marine biofilms' structure, composition, and detachment behavior at different shear stress levels.
To detect spectral and spatial heterogeneity in live biofilms without labeling, we created a custom imaging pipeline that captures reflectance spectra in the 600-850 nm range, targeting microbial …
Metabolite Analysis To Understand Factors Limiting Microbial Fermentation At High Substrate Concentrations, Bishal D. Sharma
Metabolite Analysis To Understand Factors Limiting Microbial Fermentation At High Substrate Concentrations, Bishal D. Sharma
Dartmouth College Ph.D Dissertations
Clostridium thermocellum, a thermophilic anaerobic bacterium, holds promise as a biocatalyst for conversion of lignocellulosic biomass into biofuels. This microbe has been subjected to various metabolic engineering strategies, including the deletion of genes encoding secondary fermentation products such as H₂, formate, acetate, and lactate, as well as the expression of heterologous genes to redirect carbon flux toward ethanol production. Despite these efforts, achieving economically viable ethanol titers remains a challenge. We hypothesized that studying how intracellular metabolite concentrations change as fermentation stops could reveal metabolic bottlenecks or regulatory mechanisms limiting ethanol production at high titers. However, metabolomics studies at …
Improved Protein Splicing Through Viral Passaging, John Smetana
Improved Protein Splicing Through Viral Passaging, John Smetana
Scholars Week
Intervening proteins (inteins) are translated as subdomains within host proteins and removed through an intein-driven splicing reaction where the flanking sequences (exteins) are joined with a peptide bond. Previously, we developed a self-removing translation reporter for labeling Ebola virus (EBOV). In this reporter, an intein (RadA) containing the fluorescent protein ZsGreen (ZsG) is inserted within the EBOV protein VP30. Upon VP30-RadA-ZsG expression from the viral genome, RadA-ZsG is removed from VP30 through the protein splicing activity of RadA, generating functional, non-tagged VP30 and functional ZsGreen. While incorporation of our VP30-RadA-ZsG fusion reporter into recombinant EBOV (rEBOV- RadA-ZsG) resulted in an …
Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers
Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers
Theses and Dissertations
Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.
To …
The Role Of Horizontal Gene Transfer In Antibiotic Resistance Amidst Prevalent Community And Healthcare-Associated Mrsa Rates, Gabrielle Nascimento
The Role Of Horizontal Gene Transfer In Antibiotic Resistance Amidst Prevalent Community And Healthcare-Associated Mrsa Rates, Gabrielle Nascimento
Honors College Theses
In recent decades, cases of community-acquired MRSA (CA-MRSA) and healthcare-associated MRSA (HA-MRSA) have been on the rise. The ability of antibiotic resistance to transfer between microorganisms greatly expands its threat to the effective treatment and containment of bacterial infections. The mecA gene is found on a mobile cassette within the Staphylococcal cell and encodes for PBP2a, an alternate version of penicillin-binding protein (PBP) with less binding affinity for β-lactam antibiotics, increasing resistance to the effects of antibiotics. The goal of this research is to investigate the horizontal transfer of the mecA gene between various Staphylococcus species as well as to …
Biochemical And Molecular Analysis Of Anr-Dependent Microoxic Fitness Factors In Pseudomonas Aeruginosa, Stacie E. Balsam
Biochemical And Molecular Analysis Of Anr-Dependent Microoxic Fitness Factors In Pseudomonas Aeruginosa, Stacie E. Balsam
Dartmouth College Ph.D Dissertations
Pseudomonas aeruginosa is a prominent opportunistic pathogen that is often found in microoxic environments like sites of infection and colony biofilms. P. aeruginosa can grow at oxygen (O2) at concentrations as little as 3 μM and also grows anaerobically by generating energy using nitrate as an alternate electron acceptor. An important way P. aeruginosa adapts to low O2 is through Anr, a transcription factor that upregulates many genes important for microoxic and anoxic fitness.
Specifically, Anr regulates mhr which encodes a hemerythrin protein (Mhr) that binds O2 with affinities relevant to microoxia and is also necessary for full fitness of …
Activities Of Cellulolytic, Amylolytic, And Secondary Metabolites From Thermophilic Actinomycetes Collected From The Heated Soil Around Cisolok Geyser, Dhian Chitra Ayu Fitria Sari, Fitria Ningsih, Mazytha Kinanti Rachmania, Akira Yokota, Wellyzar Sjamsuridzal
Activities Of Cellulolytic, Amylolytic, And Secondary Metabolites From Thermophilic Actinomycetes Collected From The Heated Soil Around Cisolok Geyser, Dhian Chitra Ayu Fitria Sari, Fitria Ningsih, Mazytha Kinanti Rachmania, Akira Yokota, Wellyzar Sjamsuridzal
Makara Journal of Science
This study investigated the antimicrobial activity, cellulolytic, and amylolytic abilities of eight thermophilic Actinomy-cetes isolated from the heated soil around the Cisolok geyser, West Java, Indonesia. Cellulolytic and amylolytic abili-ties were screened for on media by adding 1% (w/v) soluble starch and carboxymethylcellulose (CMC), respectively. Antimicrobial activity was screened for using the agar-plug diffusion method by cultivating strains on various growth media. Growth at various temperatures showed that six strains could grow up to 50 °C. Seven out of eight strains showed amylolytic ability at 40 °C and 45 °C, and only four strains did so at 50 °C. Screening …
Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica
Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica
All-Inclusive List of Electronic Theses and Dissertations
This study focuses on the bioaccumulation and biomagnification of mercury in freshwater food webs, with emphasis on bioindicators, such as macroinvertebrates, crayfish, and river otters. Despite regulatory efforts and advancements in monitoring, significant gaps remain in understanding mercury dynamics in freshwater systems—especially regarding its transport, methylation, and bioavailability across different ecosystems. To address these knowledge gaps, this study adopts a biocentric approach, emphasizing the role of living organisms in their environment. By utilizing macroinvertebrates, crayfish, and river otters as bioindicators, we aim to assess mercury bioavailability and distribution. These organisms provide varying temporal and spatial scales of mercury accumulation, offering …
Genome-Guided Isolation Of The Hyperthermophilic Aerobe Fervidibacter Sacchari Reveals Conserved Polysaccharide Metabolism In The Armatimonadota, Nancy O. Nou, Jonathan K. Covington, Dengxun Lai, Xavier Mayali, Cale O. Seymour, Juliet Johnston, Jian-Yu Jiao, Steffen Buessecker, Damon Mosier, Alise R. Muok, Nicole Torosian, Allison M. Cook, Ariane Briegel, Tanja Woyke, Emiley Eloe-Fadrosh, Nicole Shapiro, Scott G. Bryan, Savannah Sleezer, Joshua Dimapilis, Cristina Gonzalez, Lizett Gonzalez, Marlene Noriega, Matthias Hess, Ross P. Carlson, Lan Liu, Meng-Meng Li, Zheng-Han Lian, Siqii Zhu, Fan Liu, Xian Sun, Beile Gao, Ritesh Mewalal, Miranda Harmon-Smith, Ian K. Blaby, Jan-Fang Cheng, Peter K. Weber, Gabriela Grigorean, Wen-Jun Li, Anne E. Dekas, Jennifer E. Pett-Ridge, Jeremy A. Dodsworth, Marike Palmer, Brian P. Hedlund
Genome-Guided Isolation Of The Hyperthermophilic Aerobe Fervidibacter Sacchari Reveals Conserved Polysaccharide Metabolism In The Armatimonadota, Nancy O. Nou, Jonathan K. Covington, Dengxun Lai, Xavier Mayali, Cale O. Seymour, Juliet Johnston, Jian-Yu Jiao, Steffen Buessecker, Damon Mosier, Alise R. Muok, Nicole Torosian, Allison M. Cook, Ariane Briegel, Tanja Woyke, Emiley Eloe-Fadrosh, Nicole Shapiro, Scott G. Bryan, Savannah Sleezer, Joshua Dimapilis, Cristina Gonzalez, Lizett Gonzalez, Marlene Noriega, Matthias Hess, Ross P. Carlson, Lan Liu, Meng-Meng Li, Zheng-Han Lian, Siqii Zhu, Fan Liu, Xian Sun, Beile Gao, Ritesh Mewalal, Miranda Harmon-Smith, Ian K. Blaby, Jan-Fang Cheng, Peter K. Weber, Gabriela Grigorean, Wen-Jun Li, Anne E. Dekas, Jennifer E. Pett-Ridge, Jeremy A. Dodsworth, Marike Palmer, Brian P. Hedlund
Life Sciences Faculty Research
Few aerobic hyperthermophilic microorganisms degrade polysaccharides. Here, we describe the genome-enabled enrichment and optical tweezer-based isolation of an aerobic polysaccharide-degrading hyperthermophile, Fervidibacter sacchari, previously ascribed to candidate phylum Fervidibacteria. F. sacchari uses polysaccharides and monosaccharides for growth at 65–87.5 °C and expresses 191 carbohydrate-active enzymes (CAZymes) according to RNA-Seq and proteomics, including 31 with unusual glycoside hydrolase domains (GH109, GH177, GH179). Fluorescence in-situ hybridization and nanoscale secondary ion mass spectrometry confirmed rapid assimilation of 13C-starch in spring sediments. Purified GHs were optimally active at 80–100 °C on ten different polysaccharides. Finally, we propose reassigning Fervidibacteria as a class …
Limits Of Longwood's Electron Microscope: A Study In Biological Imaging, Rachel Danzitz, Bjoern Ch. Ludwar
Limits Of Longwood's Electron Microscope: A Study In Biological Imaging, Rachel Danzitz, Bjoern Ch. Ludwar
Fall Showcase for Research and Creative Inquiry
This study evaluates the imaging capabilities and limitations of the Hitachi TM4000II Plus Scanning Electron Microscope (SEM) and its Scanning Transmission adapter in biological imaging. A variety of specimens, including protozoans (e.g., Volvox and nematodes), bacteria (e.g., Magnetospirillum gryphiswaldense, Bacillus cereus, and Escherichia coli), tissue samples, and blood, were analyzed. While the SEM effectively imaged protozoans and bacteria, its ability to visualize viruses was deemed impractical. Despite claims of magnification up to 100,000x, clarity significantly decreased beyond 5,000x. The transmission adapter proved functional but challenging to operate consistently. The study highlights the microscope's limitations in producing high-clarity, …
Pilz Domain-Containing Proteins Regulate Motility In Acinetobacter Baumannii, Gabriel Smith
Pilz Domain-Containing Proteins Regulate Motility In Acinetobacter Baumannii, Gabriel Smith
Electronic Theses and Dissertations
Acinetobacter baumannii is an increasingly multidrug-resistant pathogen contributing to hospital-acquired infections, necessitating a greater understanding of how it interacts with its surroundings. Many bacteria utilize different methods of bacterial motility to move about and interact with these surroundings. A bacterial second messenger, cyclic diguanosine monophosphate (c-di-GMP), can regulate various motility factors that are potentially advantageous for survival in and adaptation to their environment. Concentrations of c-di-GMP are regulated by specific synthesizing and degrading enzymes. Controlled levels of c-di-GMP allow interaction between the c-di-GMP and its binding effectors that induce changes in bacterial phenotypes such as biofilm formation and motility. A …
Characterizing Enterobacter Cloacae Genetic Elements Responsible For Interactions With Candida Albicans, Abigail Suarez
Characterizing Enterobacter Cloacae Genetic Elements Responsible For Interactions With Candida Albicans, Abigail Suarez
Electronic Theses and Dissertations
Polymicrobial interactions are an important, yet understudied area of research. Candida albicans is the most common human fungal pathogen. The bacterial genus, Enterobacter, is a source of nosocomial acquired infections and increased drug resistance. Our lab has previously discovered that Enterobacter preferentially adheres to C. albicans hyphae. From an E. cloacae transposon library screen, six candidates displayed reduction in C. albicans attachment. These candidates were identified genetically and characterized for involvement in attachment to C. albicans. A fluorescent plasmid was introduced into E. cloacae to measure and observe adherence to C. albicans in planktonic and biofilm growth. In vivo …
The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh
The Physiological Significance Of Nitric Oxide Synthase In Staphylococci, Ryan M. Singh
Theses & Dissertations
Staphylococci, particularly Staphylococcus epidermidis, are common causes of implant-associated infections that may result in notable morbidity and mortality. One of the ways the innate immune system attempts to combat these invading pathogens is via the respiratory burst, in which free radical species such as nitric oxide (NO•), toxic to bacterial respiration, are released in large quantities. Despite the toxicity of NO•, some bacteria, including staphylococci, encode an endogenous bacterial nitric oxide synthase (bNOS), whose physiological role has been unclear until now. In this dissertation, we demonstrate that S. epidermidis is able to overcome the toxicity …
Growth Of Methanogens On Kaolinite, A Clay That Has Been Identified On Mars, Hailey Littrell
Growth Of Methanogens On Kaolinite, A Clay That Has Been Identified On Mars, Hailey Littrell
Biological Sciences Undergraduate Honors Theses
Methanogens have been studied as a model for life on Mars for 28 years now in the Kral lab. The discovery of methane in the Martian atmosphere by ground-based and orbital observations as well as Curiosity Rover (Formisano, V. et al., Krasnopolsky, V.A. et al., Mumma, M.J. et al.) has added relevance to these types of studies. Methanogens were chosen due to their ability to live in harsh environments, very similar to the Martian terrain. In addition to methane in the atmosphere, phyllosilicate clays have also been identified. One of those clays is kaolinite. Kaolinite has been found to not …
Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick
Characterizing The Role Of Pa5189 Of Pseudomonas Aeruginosa In Deletion And Overexpression Mutants, Seh Na Mellick
Theses/Capstones/Creative Projects
In the context of rising multidrug resistance in biofilm-forming pathogens like Pseudomonas aeruginosa, this study investigates the role of the understudied transcription factor PA5189 in antibiotic resistance and biofilm formation. PA5189 deletion and overexpression mutants were created in a parent P. aeruginosa strain using pEX18Tc-based recombinant suicide vectors, with genotypic verification of putative triparental conjugants achieved through restriction digestion and PCR. The study revealed that PA5189 overexpression significantly increases resistance to commonly used broad spectrum antibiotics such as ciprofloxacin and imipenem. Additionally, differential expression of PA5189 was found to notably affect biofilm formation, with variations contingent on the nutrient …
Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin
Managing Stress: A Study Of Stress Response Mechanisms In Mycobacteria, Augusto C. Hunt Serracin
Biology Dissertations - Archive
Mycobacteria encompass many pathogenic species known to cause severe disease in humans. A well-known example is Mycobacterium tuberculosis (Mtb), the causative agent of the lung disease tuberculosis, which kills millions of humans worldwide yearly. Pathogenic mycobacteria like Mtb are challenging to treat because of their innate ability to adapt to environmental stress. Their unique cell physiology and conserved stress responses allow them to combat biological insults, regulate growth, and regulate genes involved in stress; all these responses increase tolerance to antibiotics. The current therapies to treat mycobacterial infections are lengthy and, at times, unsuccessful, partly due to antibiotic tolerance. A …
A New Model For Polar Growth In Mycobacteria: The Role Of Wag31 And Mmpl3 In Cell Wall Synthesis, Neda Habibi Arejan
A New Model For Polar Growth In Mycobacteria: The Role Of Wag31 And Mmpl3 In Cell Wall Synthesis, Neda Habibi Arejan
Biology Dissertations - Archive
The disease Tuberculosis (TB) is caused by the pathogen Mycobacterium tuberculosis and was the cause of over one million deaths worldwide in 2023 (World Health Organization, 2023). TB treatment is difficult due to antibiotic tolerance and emerging resistance in Mtb strains. Mycobacterial cells have different regulatory mechanisms that allow them to adjust to myriad environmental stressors: these responses often lead to antibiotic tolerance. Therefore, studying responses to stress will lead to insights about antibiotic tolerance and treatment failure. Here, we specifically study two essential mycobacterial proteins, Wag31 and MmpL3, involved in cell wall metabolism. We show that Wag31 has distinct …