Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

PDF

Theses/Dissertations

Microbiology

Discipline
Institution
Publication Year
Publication

Articles 1 - 30 of 235

Full-Text Articles in Life Sciences

Urban Stream Syndrome And The Presence Of E. Coli In Philadelphia Streams, Eileen Black Nov 2019

Urban Stream Syndrome And The Presence Of E. Coli In Philadelphia Streams, Eileen Black

HON499 projects

In this experiment, water samples were collected from the Pennypack and Wissahickon Creeks as part of an exploratory study on the presence of microbes, particularly Escherichia coli, in urban streams. Contamination by E. coli may indicate that a creek is polluted and suffering from urban stream syndrome. E. coli was found in both creeks, likely due to their locations near a sewage treatment facility and a farm.


Effect Of Storage Temperature On The Survival Or Growth Of Listeria Monocytogenes On Whole And Fresh-Cut Produce, Juan F. Moreira Calix Nov 2019

Effect Of Storage Temperature On The Survival Or Growth Of Listeria Monocytogenes On Whole And Fresh-Cut Produce, Juan F. Moreira Calix

LSU Master's Theses

Whole and fresh-cut produce are minimally processed and, therefore susceptible to microbial contamination. This study examined the survival or growth of Listeria monocytogenes on whole, and fresh-cut produce at different storage temperatures. Fresh fruits (cantaloupes, pears, pineapples, papayas, and watermelon) and vegetables (broccoli, cauliflower, lettuce, kale, and green bell peppers) were cut into 25 g pieces and were spot inoculated with 0.5 mL (8 Log CFU/mL) of Listeria monocytogenes. Inoculated fresh-cut samples were stored at 4°C or 13°C for 6 days. To represent the outer surface of the produce, cantaloupes and green bell pepper disks (20 ...


Fungi In A Hot, Dry, Changing World, Miriam I. Hutchinson May 2019

Fungi In A Hot, Dry, Changing World, Miriam I. Hutchinson

Biology ETDs

My doctoral work focused on understanding the reciprocal relationship between fungi and their environment, namely how fungi respond to environmental flux, as well as how fungi can modify and structure their habitats, especially in the context of climate change. As such, I aimed my research on fungi with distinct adaptations to their environmental niches: endophytic fungi that inhabit plant tissue and thermophilic fungi that are capable of growing at the upper temperature limit for eukaryotic life. My research consisted of three studies. First, I investigated the thermophilic species Myceliophthora heterothallica to demonstrate its use as a model organism for efficient ...


Mining For Biological Control Agents Against B. Glumae, The Causal Agent Of Bacterial Panicle Blight Of Rice., Katherine Anne Wilkinson May 2019

Mining For Biological Control Agents Against B. Glumae, The Causal Agent Of Bacterial Panicle Blight Of Rice., Katherine Anne Wilkinson

Theses and Dissertations

Burkholderia glumae is the causal agent of the emerging disease, Bacterial Panicle Blight of rice, a serious disease that can significantly decrease yield and poses a threat to rice production worldwide. This thesis is concerned with searching for a biological control agent to control this disease. Plant associated microbes are a good source of beneficial bacteria which can be exploited for use as a biological control agent. It is possible that the microbiomes of cultivars which are known to be more resistant to plant pathogens may contain more microbes which inhibit those pathogens and therefore could be used as biological ...


A Trio Of Sigma Factors Control Hormogonium Development In Nostoc Punctiforme, Alfonso Gonzalez Jr. Jan 2019

A Trio Of Sigma Factors Control Hormogonium Development In Nostoc Punctiforme, Alfonso Gonzalez Jr.

University of the Pacific Theses and Dissertations

Cyanobacteria are prokaryotes capable of oxygenic photosynthesis, and for many species, nitrogen fixation, giving cyanobacteria an important role in global carbon and nitrogen cycles. Furthermore, multicellular filamentous cyanobacteria are developmentally complex, capable of differentiation into different cell types, including cells capable of nitrogen fixation and cells for motility, making them an ideal platform for studying development, as well as for practical use in biotechnology. Understanding how developmental programmes are activated require an understanding of the role of alternative sigma factors, which are required for transcriptional activation in bacteria. In order to investigate the gene regulatory network and to determine the ...


Analysis Of The Thermal Stability Of A Diverse Panel Of Respiratory Syncytial Virus (Rsv) Strains, Darby Deford Jan 2019

Analysis Of The Thermal Stability Of A Diverse Panel Of Respiratory Syncytial Virus (Rsv) Strains, Darby Deford

Undergraduate Honors Thesis Collection

Respiratory syncytial virus (RSV) is a major respiratory pathogen of young infants and the elderly and is associated with upper and lower respiratory disease. Vaccine development for RSV has been hindered by poor immunogenicity in target populations, genetic and physical instabilities, and a legacy of vaccine-enhanced disease. The fusion and attachment proteins of RSV, F and G, have been seen to be responsible for inducing the majority of neutralizing antibodies. However, little remains known about how differences in RSV F and G affect virus replication and stability. In this thesis, we proposed to examine the replication and thermal stability of ...


Enhanced Expression Of Receptor Tyrosine Kinase Mer (Mertk) On Socs3-Treated Polarized Raw 264.7 Anti-Inflammatory M2c Macrophages, Sankhadip Bhadra Jan 2019

Enhanced Expression Of Receptor Tyrosine Kinase Mer (Mertk) On Socs3-Treated Polarized Raw 264.7 Anti-Inflammatory M2c Macrophages, Sankhadip Bhadra

Browse all Theses and Dissertations

Macrophages are phagocytic cells located in tissues, organs and even circulated within our body as white blood cells. They are critical in detecting tissue damage and infection. Resident tissue macrophages initiate the signals for inflammation recruiting neutrophils and blood monocytes which mature into macrophages at sites of infection and in the resolution of inflammation. Based on the local cytokine milieu in tissue sites, macrophages may be polarized into pro-inflammatory M1 or anti-inflammatory M2 phenotypes. Receptor tyrosine kinase Mer (MERTK) helps in clearing dead neutrophils and other apoptotic cells from damaged tissue sites preventing chronic inflammation and autoimmune disorders. MERTK aids ...


The Effects Of Socs1 And Socs3 Peptide Mimetics On Macrophage Phagocytosis Of Malignant Cells, Tahirah M. Madkhali Jan 2019

The Effects Of Socs1 And Socs3 Peptide Mimetics On Macrophage Phagocytosis Of Malignant Cells, Tahirah M. Madkhali

Browse all Theses and Dissertations

Macrophages are essential phagocytic cells involved in both innate and adaptive immune systems and play vital roles in the host defense and inflammation. Macrophages have a remarkably high capacity to clear unnecessary cellular materials in interstitial environment through a process called “phagocytosis”, which is affected by many factors including suppressors of cytokine signaling (SOCS). SOCSs are a group of intracellular proteins that downregulate the cytokine signals involved in various JAK/STAT pathways through a negative feedback loop. This study focuses on investigating the effects of SOCS1 and SOCS3 on the phagocytic ability of RAW 264.7 macrophages polarized into M2a ...


Six-Nine Months Long Term Culture Of Mouse Bone Marrow Cells Differentiated To Macrophages And Eosinophils, Olena B. Svitlova Jan 2019

Six-Nine Months Long Term Culture Of Mouse Bone Marrow Cells Differentiated To Macrophages And Eosinophils, Olena B. Svitlova

Browse all Theses and Dissertations

Mouse models of eosinophil-associated diseases have been used to study the mechanisms of disease pathogenesis. In this study, mouse-derived bone marrow cells were used in long-term (6 and 9 months) cell cultures of differentiated eosinophils and macrophages. IL-5 was used to differentiate the stem cells to eosinophils and GM-CSF was used to propagate macrophages from the bone marrow stem cells. The maximum time period for observing the eosinophil cultures was 252 days which is censurably longer than the 18 days culture period observed by others. The results were assessed by describing the microscopic cell morphology by Wright staining, modified Giemsa ...


Microbial Ecology Of South Florida Surface Waters: Examining The Potential For Anthropogenic Influences, Chase P. Donnelly Aug 2018

Microbial Ecology Of South Florida Surface Waters: Examining The Potential For Anthropogenic Influences, Chase P. Donnelly

HCNSO Student Theses and Dissertations

South Florida contains one of the largest subtropical wetlands in the world, and yet not much is known about the microbes that live in these surface waters. These microbes play an important role in chemical cycling and maintaining good water quality for both human and ecosystem health. The hydrology of Florida’s surface waters is tightly regulated with the use of canal and levee systems run by the US Army Corps of Engineers and The South Florida Water Management District. These canals run through the Everglades, agriculture, and urban environments to control water levels in Lake Okeechobee, the Water Conservation ...


Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor May 2018

Functional Similarity Of Prd-Containing Virulence Regulators In Bacillus Anthracis, Malik Raynor

UT GSBS Dissertations and Theses (Open Access)

Bacillus anthracis produces three regulators, AtxA, AcpA, and AcpB, that control virulence gene expression and are members of an emerging class of regulators termed “PCVRs” (Phosphoenolpyruvate-dependent phosphotransferase regulation Domain-Containing Virulence Regulators). AtxA controls expression of the toxin genes; lef, cya, and pag, and is the master virulence regulator and archetype PCVR. AcpA and AcpB are less well studied. AcpA and AcpB independently positively control transcription of the capsule biosynthetic operon capBCADE, and culture conditions that enhance AtxA activity result in capBCADE transcription in strains lacking acpA and acpB. RNA-Seq was used to assess the regulons of the paralogs in strains ...


Study Of Rheological, Chemical, And Microbiological Properties Of Chami, A Traditional Emirati Soft Chees, Aysha Othman Abdullah Al Katheeri Apr 2018

Study Of Rheological, Chemical, And Microbiological Properties Of Chami, A Traditional Emirati Soft Chees, Aysha Othman Abdullah Al Katheeri

Theses

In this work, ten Emirati Chami cheese samples were collected and analyzed to determine their chemical composition, texture, rheology, and microbiological properties. Chami cheeses showed large variations in moisture (60.9–84.1%), protein (7.5–14.6%), fat (0.5–7.8%), and ash (3.4–8.0%) contents as well as in pH (3.6–4.4), and water activity (0.977–0.999%). The variation in fat content of samples suggested that extra fat was added; this added fat was either butter or vegetable oil as indicated by the fatty acid composition. The different samples showed peaks ...


A Cure For Salmonella: Engaging Students In Pathogen Microbiology And Bioinformatics, Sophie Jurgensen Jan 2018

A Cure For Salmonella: Engaging Students In Pathogen Microbiology And Bioinformatics, Sophie Jurgensen

Senior Honors Projects, 2010-current

Advances in Next Generation Sequencing (NGS) technology have generated a vast amount of publicly available genomic data, creating a need for students with training in computational analysis. This laboratory lesson is a course-based undergraduate research experience (CURE) focusing on environmental Salmonella, a common foodborne pathogen that is of great interest to public health laboratories but is relatively less virulent than most other such pathogens. As discovery is a central tenet of CUREs, students isolate novel Salmonella enterica and related strains from stream sediment, poultry litter, or other sources in the first half of the lesson (Module 1). They also conduct ...


The Effects Of Housing On Dairy Cow Comfort, Immune Function, Stress, Productivity, And Milk Quality, Matthew Richard Borchers Jan 2018

The Effects Of Housing On Dairy Cow Comfort, Immune Function, Stress, Productivity, And Milk Quality, Matthew Richard Borchers

Theses and Dissertations--Animal and Food Sciences

Mastitis and milk quality affect every dairy farmer across the globe. Sand bedded freestalls are the industry standard for cow comfort, welfare, and the control of environmental mastitis. Compost bedded packs may be a viable alternative to the sand bedded freestall.

Compost bedded packs are maintained at a consistent level of moisture, nutrients, and aeration to favor compost microorganisms. Greater bacteria counts in bedding have traditionally been associated with increased mastitis rates and mastitis pathogens can be found in the pack and on the teats of cattle housed in even well managed compost bedded pack barns. In spite of this ...


Virus Production And Cell Viability Of Hsv-1-Infected Murine Keratinocytes (Hel-30) Co-Cultured With Murine Macrophages (Raw 264.7), Barry Graffagna Jan 2018

Virus Production And Cell Viability Of Hsv-1-Infected Murine Keratinocytes (Hel-30) Co-Cultured With Murine Macrophages (Raw 264.7), Barry Graffagna

Browse all Theses and Dissertations

Keratinocytes are the most abundant type of cell in the outer layer of skin, the epidermis, and provide barrier against pathogens from invading. However, Herpes Simplex Virus Type 1 (HSV-1) targets these keratinocytes for infection, and later infects neurons to establish lifelong latency. The keratinocytes stimulate the innate immune system to engage and to destroy the virus. Among the cells of the innate immune system to respond to the viral invasion is the macrophage. In this study, RAW 264.7 macrophage and HEL-30 keratinocyte monolayers were challenged in vitro with HSV-1 at a multiplicity of infection (MOI) of 0.1 ...


Optimizing Transposon Mutagenesis In Vibrio Strains To Identify Genes Involved In Antibiotic Production, Mahnur Khan Dec 2017

Optimizing Transposon Mutagenesis In Vibrio Strains To Identify Genes Involved In Antibiotic Production, Mahnur Khan

Honors Projects

Based on previous studies that have shown the competitive nature of non-pathogenic environmental strains of Vibrio, we hypothesize that environmentally derived bacteria can inhibit Vibrio pathogens, and possibly be a source of novel antibiotics. A previous experiment performed in the lab tested environmental Vibrio strains from various habitats against the pathogenic strains, Vibrio cholerae and Vibrio parahaemolyticus. Of the 3,456 strains collected, members of the Wildschutte lab identified 102 environmental strains of Vibrio that inhibited the growth of both pathogens. The data suggests that environmental Vibrio strains directly inhibit the growth of related pathogens. Our project involves the identification ...


Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres Dec 2017

Comparing The Effectiveness Of Alternative And Prescription Antibiotics Against Gram-Positive Bacteria, Rachel Jenkins, Roan Dickenson, Sam Turnbull, Marcela Torres

Senior Theses

The rapid emergence of antibiotic-resistant bacteria is a global public health concern that threatens the efficacy of antibiotic drugs. We found that natural remedies, specifically coconut oil, honey and cinnamon essential oil, have the potential to be used as a clinical alternative to treat antibiotic-resistant infections. In this experiment, we performed a disk diffusion test and measured the area of inhibition of each treatment to compare the effectiveness of natural and prescription antibiotics. Cinnamon essential oil showed significantly greater antibiotic activity compared to a prescription treatment, amoxicillin. With bacterial resistance continuously expanding, more work needs to be done to determine ...


Microbial And Genomic Analysis Of Environmental Samples In Search Of Pathogenic Salmonella, Jorie L. Skutas Nov 2017

Microbial And Genomic Analysis Of Environmental Samples In Search Of Pathogenic Salmonella, Jorie L. Skutas

HCNSO Student Theses and Dissertations

Salmonellosis or “food poisoning” is a foodborne infection brought on by the pathogen Salmonella from the ingestion of the bacterium on contaminated foods such as vegetables. Infection from Salmonella leads to the highest incidence of hospitalizations and deaths each year, compared to any other bacterial foodborne illness. South Florida is the second largest agricultural winter vegetable producer in the United States, and contamination of vegetables is often observed in preharvest practices. A hardy bacterium, Salmonella, has been shown to live up to 6 weeks in soil and water up to 42°C without a host.

The Florida Everglades is a ...


Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol Aug 2017

Growth And Survivability Of Microorganisms At Martian Temperatures And Pressures, Rebecca Lynne Mickol

Theses and Dissertations

The discovery of methane in the martian atmosphere via numerous ground- and space-based sources has prompted the study of methanogens as models for life on Mars. Methanogens are microorganisms within the domain Archaea, many of which utilize carbon dioxide (CO2) and hydrogen to produce methane. The non-photosynthetic nature of methanogens indicates that they could exist in sub-surface environments, protected from harmful UV and ionizing radiation on the surface of Mars. These organisms also do not require organics, which are sparse on the planet.

Additionally, the wide variety of environments we find life in on Earth, as well as evidence for ...


Microbial Community Richness Distinguishes Shark Species Microbiomes In South Florida, Rachael Cassandra Karns Jul 2017

Microbial Community Richness Distinguishes Shark Species Microbiomes In South Florida, Rachael Cassandra Karns

HCNSO Student Theses and Dissertations

The microbiome (microbial community) of individuals is crucial when characterizing and understanding processes that are required for organism function and survival. Microbial organisms, which make up an individual’s microbiome, can be linked to disease or function of the host organism. In humans, individuals differ substantially in their microbiome compositions in various areas of the body. The cause of much of the composition diversity is yet unexplained, however, it is speculated that habitat, diet, and early exposure to microbes could be altering the microbiomes of individuals (Human Microbiome Project Consortium, 2012b, 2012a). To date, only one study has reported on ...


Engineering Synthetic Antibiotics In Non-Traditional Pathways To Counter Antibiotic Resistance, Colleen Maxwell Courtney Jan 2017

Engineering Synthetic Antibiotics In Non-Traditional Pathways To Counter Antibiotic Resistance, Colleen Maxwell Courtney

Chemical & Biological Engineering Graduate Theses & Dissertations

Antibiotic resistance is a growing threat to global healthcare that requires immediate action to avoid the post-antibiotic era. The inherent ability of bacteria to obtain resistance and the lack of new antibiotics has led to the current antibiotic crisis. Current antibiotics are typically found through soil compound screens and only target proteins within three cellular pathways: cellular replication, cell wall biosynthesis, and protein biosynthesis. In the last decade, strains have been isolated which have resistance to nearly all available antibiotics highlighting the urgent need for intervention. In this work we investigated the rational design of non-naturally derived antibiotics which target ...


Antibiotic Resistance Genes In Minnesota Soil Bacteria From Areas Of High And Low Ferric Iron, Gunner L. Drossel, Presley Martin Phd Jan 2017

Antibiotic Resistance Genes In Minnesota Soil Bacteria From Areas Of High And Low Ferric Iron, Gunner L. Drossel, Presley Martin Phd

Departmental Honors Projects

Naturally-occurring antibiotic resistance genes in soil bacteria represent a potentially important reservoir of genes that could contribute to antibiotic resistance of human pathogens. It has been reported that over 40 genes in bacterial genomes are controlled by concentrations of ferric iron. We examined the effect of soil metal content on the level of resistance to two antibiotics, ampicillin (Amp) and tetracycline (Tet), and the presence of multiple genes that code for efflux pump-mediated resistance. These pumps act to export toxins (e.g. heavy metals and antibiotics, perhaps). Because of this, growth in heavy metal-contaminated soils might select for antibiotic resistance ...


A Novel Periplasmic Protein Involved In The Mannan Chain Elongation Step Of Lipomannan And Lipoarabinomannan Biosynthesis In Mycobacterium Smegmatis, Stephanie A. Ha Jan 2017

A Novel Periplasmic Protein Involved In The Mannan Chain Elongation Step Of Lipomannan And Lipoarabinomannan Biosynthesis In Mycobacterium Smegmatis, Stephanie A. Ha

Masters Theses

Mycobacteria are atypical bacteria possessing unusual cell envelopes comprised of an outer membrane, covalently linked to an arabinogalacatan-peptidoglycan structure via waxy mycolic acids, in addition to the conventional inner membrane. This thick and highly impermeable cell envelope is a major deterrent to antibiotic treatment of clinically relevant mycobacterial pathogens, including Mycobacterium tuberculosis (Mtb), which infects a third of the world’s population and kills millions each year. Thus, the regulation of mycobacterial cell envelope biosynthesis is of great interest for the development of more effective therapeutics for treating Mtb infections. Using the model organism Mycobacterium smegmatis (M. smegmatis), we identified ...


The Impact Of Socs1 And Socs3 Peptide Mimetics On Rho And Cdc42 Proteins Expression, F-Actin Cytoskeleton Rearrangements, And Cytokines Production Of Uninfected And Hsv-1 Infected M1 And M2 Raw 264.7 Murine Macrophages, Maha A. Elwardany Jan 2017

The Impact Of Socs1 And Socs3 Peptide Mimetics On Rho And Cdc42 Proteins Expression, F-Actin Cytoskeleton Rearrangements, And Cytokines Production Of Uninfected And Hsv-1 Infected M1 And M2 Raw 264.7 Murine Macrophages, Maha A. Elwardany

Browse all Theses and Dissertations

The immune system plays an essential role in the pathogenesis of HSV-1 during the lytic phase of the disease, orchestrating the inflammatory response, retaining the virus in its latent phase and preventing the recurrence of HSV-1 infection. Macrophages display a vital role in the innate and adaptive immune responses during multiple phases of HSV-1 infection. Polarized macrophages are categorized into two distinct classes with diverse functions. The classically activated M1 can engulf and destroy the microbial agents, produce proinflammatory cytokines, and participate in the pathogenesis of many inflammatory diseases. The alternatively activated M2 induces anti-inflammatory mediators and stimulates tissue remodeling ...


Effect Of Exposure Of Raw264.7 Macrophages To Salmonella Typhimurium Components On Cell Viability, Cytoskeleton Re-Arrangement And Cytokine Secretion, Khalid Abdullah Alyahya Jan 2017

Effect Of Exposure Of Raw264.7 Macrophages To Salmonella Typhimurium Components On Cell Viability, Cytoskeleton Re-Arrangement And Cytokine Secretion, Khalid Abdullah Alyahya

Browse all Theses and Dissertations

Innate immune system plays an important role in individual's protection against pathogens and in activation of adaptive immune system. Utilizing RAW 264.7 murine macrophages as an innate immune response representative in this study, we analyzed the effect of invasive pathogen's components (e.g. flagellin) on the arrangement of macrophage's cytoskeleton, on viability of immune cells and on secretion of pro-inflammatory and anti-inflammatory cytokines and on fluorescence intensity of cytoskeleton after rearrangement. Additionally, we studied the similarity and differences between bacterial (Salmonella typhimurium) and synthetic TLR4 agonist (synthetic lipid-A) on viability, fluorescence intensity, cytokine secretion, and cytoskeleton ...


Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner Jan 2017

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner

Theses and Dissertations (Comprehensive)

Bacteria thrive within multicellular communities called biofilms consisting of a self-produced matrix. Biofilm matrices improve bacterial adherence to surfaces while creating a barrier from host immune responses, disinfectants, antibiotics and other environmental factors. Persistent colonization by the widely distributed pathogens, Escherichia coli and Salmonella spp., has been linked to production of biofilms composed of the exopolysaccharide cellulose. Cellulose-containing biofilms are also important to Acetobacter, Sarcina, Rhizobium and Agrobacterium species to form symbiotic and pathogenic interactions. In Enterobacteriaceae, two operons (bcsABZC and bcsEFG) are proposed to encode for proteins that form a cellulose biosynthetic complex that spans the bacterial cell wall ...


Population Genetics Of Borrelia Burgdorferi In The Eastern And Midwestern United States, Stephanie Nicole Seifert Jan 2017

Population Genetics Of Borrelia Burgdorferi In The Eastern And Midwestern United States, Stephanie Nicole Seifert

Publicly Accessible Penn Dissertations

Changes in climate and land-use are influencing the spatial distributions and population structure of species throughout the world. Among those species predicted to be affected by changes in climate and land-use are the hosts and vectors of many zoonotic pathogens, including the hosts and vectors of the Lyme borreliosis pathogen, Borrelia burgdorferi. In this study, we investigate the population structure of B. burgdorferi at the interface of two expanding vector populations using a population genetic and phylogeographic approach. We then examine the influence of recombination between major B. burgdorferi lineages on the population structure of B. burgdorferi within and between ...


The Function Of Renalase, Brett Allen Beaupre Aug 2016

The Function Of Renalase, Brett Allen Beaupre

Theses and Dissertations

Renalase was originally reported to be an enzyme secreted into the blood by the kidney to lower blood pressure and slow heart rate. Despite multiple reports claiming to confirm this activity in vivo there has been considerable discord in regards to the reaction catalyzed by renalase. The structural topology of renalase resembles that of known flavoprotein oxidases, monooxygenases and demethylases, but the conserved active site residues are unique to renalase. It has been reported that the catalytic function of renalase is to oxidize circulating catecholamines, however in vitro studies have failed to demonstrate a catalytic activity in the presence of ...


Characterization Of The Marine Sponge Amphimedon Compressa Microbiome Across A Spatial Gradient, Renee Michelle Potens May 2016

Characterization Of The Marine Sponge Amphimedon Compressa Microbiome Across A Spatial Gradient, Renee Michelle Potens

HCNSO Student Theses and Dissertations

Diverse and ecologically important microbial communities (microbiomes) are symbiotic within marine sponges. In this study, the microbiome of Amphimedon compressa from three sample locations (Broward and Dade Counties, Southeast Florida, USA and the Southern Caribbean, Bocas del Toro, Panama) is characterized using 16S rRNA Illumina sequencing. The predominant taxa are Proteobacteria and Cyanobacteria, as expected for Low Microbial Abundance sponges, accounting for over 53% of the total microbiome community. The numbers of Operational Taxonomic Units (OTUs) decrease from Broward County (2,900) to Dade County (2,300) and then Bocas del Toro (1,200). The correlates to a decreasing north-south ...


Protective Effects Of Pigmentation In Pseudomonas Aeruginosa: Insights On Pyomelanin Production And Inhibition By Ntbc, Laura Marie Ketelboeter May 2016

Protective Effects Of Pigmentation In Pseudomonas Aeruginosa: Insights On Pyomelanin Production And Inhibition By Ntbc, Laura Marie Ketelboeter

Theses and Dissertations

Pyomelanin is an extracellular, reddish-brown pigment produced by several environmental and pathogenic bacteria and fungi. It is derived from the phenylalanine/tyrosine catabolism pathway and is produced when homogentisate (HGA) is secreted from the cell, auto-oxidized, and self-polymerized. Point mutations or chromosomal deletions in hmgA, which encodes homogentisate 1,2-dioxygenase, result in the accumulation of HGA and subsequent pyomelanin production. My work showed that the pyomelanogenic Pseudomonas aeruginosa clinical isolate PA1111 had a chromosomal deletion of hmgA, while a second pyomelanogenic clinical isolate, DKN343, had a loss of function mutation in HmgA. The 4-hydroxyphenylpyruvate dioxygenase (Hpd) inhibiting compound 2-(2-nitro-4-trifluoromethylbenzoyl ...