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Uv-A Light: A Novel Method For Food Dehydration, Mckade S. Roberts

All Graduate Theses and Dissertations, Fall 2023 to Present

Dehydration is one of the most prevalent forms of food preservation, with approximately 85% of food is hot air drying due to the simplicity of the process. The high temperatures employed in this method may also induce a loss in nutritional quality, which involves destruction of micronutrients (vitamins), and loss of color.

The aim of this work is to develop a low energy, non-thermal method of food dehydration that results in a high-quality product through the application of Ultraviolet light, within the UV-A range. UV light can be separated into its 3 categories based on the wavelength of light from …

Antimicrobial Activity Of Cat Flea (Ctenocephalides Felis) Gut Proteins On Different Days After Blood Feeding, Dhruva K. Karnik

Honors College Theses

Cat fleas (Ctenocephalides felis) are a blood-feeding ectoparasitic insect and a common domestic pest found throughout the world. Because of their reliance on host blood, fleas are exposed to blood-borne pathogens; however, the flea gut lumen is a hostile environment for microbial colonization. For example, the gut epithelia differentially express immune genes in response to feeding. In the present study, we measured the antimicrobial activity of gut proteins from cat fleas at different days after feeding (2, 5, 7, and 14). Dissected flea guts were homogenized, passed through a syringe filter, and measured in a protein assay kit. …

Understanding And Developing Safer Sanitation Agents And Strategies In Food Production Environments, Pragathi Kamarasu

Doctoral Dissertations

Food is a primary resource for survival of human beings, and it is also one of the primary resources for spread of infectious diseases. When both these factors come together it does not only cause ill effects on our health but also causes a burden on the food and agricultural industry. Through the help of science, us researchers and scientists have always tried to reduce this burden. And I hope like a drop of water in the ocean in some way my research contributes towards this. According to WHO currently in 2023 there are about 1 in 10 people falling …

Rapid Prediction Of Phonon Density Of States By Graph Neural Network And High-Throughput Screening Of Candidate Substrates For Wide Bandgap Electronic Cooling, Mohammed Saif Ali Al-Fahdi

Theses and Dissertations

Machine learning has demonstrated superior performance in predicting vast materials properties. However, predicting a continuous material property such as phonon density of states (DOS) is more challenging for machine learning due to the inherent issues of data smoothing and sensitivity to peak positions. In this work, phonon DOS of 2,931 inorganic cubic structures with 63 unique elements from the Open Quantum Materials Database are calculated by high precision density functional theory (DFT). With these training data, we build an equivariant graph neural network (GNN) for total phonon DOS of crystalline materials that utilizes site positions and atomic species as input …

Development Of Domestic Oleochemicals For Coating Applications, Caleb M. Metzcar

Masters Theses

The overall objective of the present work is to explore new applications of soybean oil based oleochemicals. Two main applications are developed; one using soybean oil, acrylic acid, and nonthermal plasma (NTP) treatment to dye para-aramids with cationic and non-ionic pigments, the other using fatty acids to synthesize waxes with bound quaternary ammonium compounds (QAC), an antimicrobial functional group, for fruit and vegetable postharvest coating. The color strength of the dyed fabric was quantified and the effect of the dyeing on material strength was evaluated to identify the optimal treatment condition. Antimicrobial waxes have been successfully developed that some structures …

Characterization Of Antimicrobial Properties Of Excrement And Functional Microbiome Of Black Vultures (Coragyps Atratus), Bridgette Gray

Theses

Black vultures, Coragyps atratus, are obligate scavenging birds that consume and dispose of decaying carcasses and carrion. They fulfill a key ecological niche in the environments in which they live. It has been observed that these vultures sometimes excrete bodily waste onto their legs. This adaptive behavior could help aid them in controlling bacteria and other microbes they encounter while stepping into a carcass to eat. This study directly examined the antimicrobial properties of the excrement of black vultures across various bacterial species utilizing a zone of inhibition test and a nematode species utilizing a survival assay. The black vulture …

Anaerobic Digestion Of Brewery Waste Including Spent Yeast And Hops, Dhanashree Rawalgaonkar

USF Tampa Graduate Theses and Dissertations

Florida is home to more than 300 craft breweries, that brew over a million barrels of beer annually. Brewing is an energy intensive process and produces large quantities of high strength waste including spent grains, yeast, hops, and high strength wastewater. Brewery wastewater, and spent yeast have high Chemical Oxygen Demand (COD) concentrations between 5000 mg/L – 10,000 mg/L, and 200,000 mg/L – 300,000 mg/L respectively. Brewery effluent wastewater is sent to Publicly Owned Treatment Works (POTWs) which implement high surcharges based on the strength of brewery effluent (COD concentration). While some of the spent yeast and hops can be …

3-D Printed Microstructures With Zno Nanoflower For Antimicrobial Applications, Henry Yuqing

Theses

Many studies have been conducted to combat the bacterial infections problem by creating antimicrobial surfaces. However, the majority of them require complex manufacturing processes and expensive equipment. In this study, a cheaper and easy to be fabricated antimicrobial surface has been developed. First, a micropatterned 3D printed structure was fabricated. Then it was coated with zinc oxide (ZnO) nanoflower. The study demonstrated that micropatterned structure served as an “armor” to the nanostructure from plastic scraper and finger abrasion. To test the antimicrobial performance of the surface, the chip was immersed in 2E8 CFU/mL Escherichia coli (E. coli) suspension and incubated …

Identification And Creation Of Novel Bacteriocins With Potential Food And Clinical Applications, David Lynch

Theses

Bacteriocins represent a heterogeneous group of small, ribosomal-synthesized, potent antibacterial peptides produced by bacteria, capable of inhibiting bacteria both closely related or indeed those from other genera than the producer. In addition to their role as food preservatives, bacteriocins have potent activity against medically significant pathogens and are considered attractive alternatives to antibiotics, due to their inherent heat stability, potency at nanomolar scale, resistance to proteases and low levels of acquired resistance in commercial applications. The aim of this thesis was to identify, purify and bioengineer novel bacteriocins from Staphylococcus and Lactic Acid Bacteria (LAB), with a view to expanding …

Isolation And Characterisation Of Soil-Derived Bacteria With Antimicrobial Activity Against Antibiotic Resistant Pathogens, Ellen Twomey

Theses

Bacteriocins are a diverse range of ribosomally synthesized bioactive peptides, recognised predominantly for their potent antimicrobial activity against other strains closely related to the producer. The focus of this thesis was to explore this activity and examine the potential of bacteriocins to inhibit the growth of clinically relevant pathogens. Although evidence exists in the literature to suggest that bacteriocins could be applied in a similar fashion to conventional antibiotics, to date they are only utilised as preservative in food to prevent the growth of foodborne illness causing organisms. Isolating and screening bacterial strains in order to identify bacteriocin producers has …

Cross-Seeding Of Protegin-1 And Amyloid Beta To Inhibit Amyloid Beta Aggregation, Sarah Robinson

Williams Honors College, Honors Research Projects

Amyloid beta (Aβ) is considered a major component in the progression of degenerative disease like Alzheimer’s disease. In an attempt to cure Alzheimer’s before it has presented, this project proposes a study on the effects of protegrin-1 (PG-1) on the aggregation of Aβ. By cross-seeding to form a PG-1- Aβ heterocomplex, it is believed that aggregation of Aβ on the human brain can be inhibited, thus helping to stop the neurodegeneration caused by Alzheimer’s disease. To complete this project, an initial literature review of previous work done by the graduate student leading the project will be completed. After this, experiments …

The Wound Healing And Antibacterial Properties Of Mesenchymal Stromal Cell Extracellular Matrix Nanoparticles, Emily N. Wandling

Theses and Dissertations

Treatments for acute respiratory distress syndrome (ARDS) are still unavailable and the prevalence of the disease has only increased due to the Covid-19 pandemic. Mechanical ventilation regiments are still utilized to support declining lung function, but they also contribute to lung damage and increase the risk of bacterial infection. The anti-inflammatory and pro-regenerative abilities of mesenchymal stromal cells (MSCs) have shown to be a promising therapy for ARDS. We propose to utilize the regenerative effects of MSC secretome and the extracellular matrix (ECM) into a nanoparticle. Our mouse MSC (MMSC) ECM nanoparticles were characterized using size, zeta-potential, and mass spectrometry …

Death Of A Bacterium: Exploring The Inhibition Of Staphylococcus Aureus By Burkholderia Cenocepacia., Tiffany Brandt

Electronic Theses and Dissertations

Antimicrobial resistance is a phenomenon of increasing concern as antimicrobial overuse and misuse eliminate current therapeutic options, ushering society into a post-antimicrobial era. Antibiotic discovery and synthesis efforts are urgently needed to counter the increasing burden of antimicrobial resistance. Staphylococcus aureus is a causative agent of a variety of clinical manifestations including bacteremia, endocarditis, soft tissue infection, osteomyelitis, and device-related infections. S. aureus infection presents additional treatment challenges due to its capacity for biofilm formation, which is a mode of growth that confers protection from antibiotics and physical elimination, and the emergence of antibiotic resistant strains, including methicillin-resistant S. aureus …

Lactic Acid Bacteria Isolated From Fresh Vegetable Products: Potential Probiotic And Postbiotic Characteristics Including Immunomodulatory Effects, Fatima Khaled Alameri

Theses

The ability to perform effectively in the gastrointestinal system (GIT) is one of the most significant criteria for selecting the best probiotic bacteria. Thus, the present study aimed to investigate the potential probiotic characteristics of some selected lactic acid bacteria (LAB) isolated from vegetable products. Probiotic characteristics included tolerance to acid and bile, cholesterol removing ability, bile salt hydrolysis, resistance against lysozyme and antibiotics, production of exopolysaccharides (EPS), antimicrobial and hemolytic activities, and cell surface characteristics (auto-aggregation, co-aggregation, and hydrophobicity). Out of 46 isolates, 17 isolates that exhibited remarkable survivability under gastrointestinal conditions were selected for further analysis. Almost all …

Towards A Robust And Long-Lasting Antimicrobial Surface, Justin A. Silva

Theses

Bacterial adhesion to surfaces such as medical devices causes approximately 1.7 million infections and 75,000 deaths each year in the United States. Throughout the past several years, many studies have been conducted on micro- and nanostructure-enabled antimicrobial surfaces. However, this idea is controversial, as some studies have shown that superhydrophobic micro and nanostructures cannot prevent bacterial growth over time and that they are not a practical solution to reduce healthcare-related infections. The objective of this study is to develop a mechanically durable and long-lasting antimicrobial surface to prevent bacterial growth. High-aspect-ratio micro mushroom structures are fabricated by high resolution stereolithography …

Enhancement In Photoinactivation Of Food-Borne Pathogenic Bacteria With The Use Of Curcumin And Surfactants, Victor Ryu

Doctoral Dissertations

Photosensitizers and UV or visible light could photoinactivate bacteria. Curcumin was utilized as a food-grade photosensitizer, and an enhancement of its water-dispersibility, chemical stability, and antimicrobial activity when introduced into surfactant solutions was observed. Stock curcumin-surfactant solutions were prepared by titrating curcumin dissolved in ethanol into either Surfynol 465 or Tween 80 solutions (5 mM sodium citrate buffer). Stock curcumin surfactant solutions with different surfactant concentrations were diluted to 1 µM prior to irradiation. The resulting solutions also had surfactant concentrations below, near, and above their critical micelle concentrations (CMCs) of the respective surfactants. The antimicrobial activity of the curcumin-loaded …

Implications Of Antibiotic And Bacteriophage Resistance In Environmentally Isolated E. Coli, Michael Connolly

Honors Theses

The increasing prevalence of antibiotic-resistant bacteria is an emerging problem for humans. Clinical misuse, overuse in agricultural and food settings, and limited numbers of new antibiotics have accelerated the proliferation of antibiotic-resistant bacteria. To confront this threat, scientists must develop new therapeutics that kill these antibiotic-resistant bacteria. In this study, we used Escherichia coli to analyze antibiotic and bacteriophage susceptibility. E. coli is a common, mostly benign, enteric, gram-negative bacteria. We isolated three E. coli strains from the Hans Groot Kill, a stream that runs through Union College’s campus. We sought to assess various E. coli strains’ antibiotic resistance, susceptibility …

Antimicrobial Assay Of Sagebrush Roots, Lauren Rachel (Moody) Mcfadden

Undergraduate Honors Capstone Projects

Plants produce secondary metabolites for various functions, one of which is antibacterial activities. Sagebrush has historically been used by Native Americans for different medicinal purposes, suggesting that it may have secondary metabolites that would have medicinal values, including antimicrobial activities, and can be a natural source for antibiotics. This study aims to carry out the antimicrobial activity of Sagebrush root extract against a handful of bacteria. We tested the antimicrobial activity of root extract of Sagebrush against six bacteria such as Bacillus subtilis, Bacillus cereus, E. coli DHSα (Lab cloning strain), Agrobacterium tumefaciens GV3101 (Lab cloning strain), Pseudomonas …

Bis(Tryptophan) Amphiphiles: Design, Synthesis And Efficacy As Antimicrobial Agents, Michael Mckeever

Dissertations

Amphiphiles play important roles in nature. These molecules contain both hydrophilic and hydrophobic regions, leading to some astonishing properties. The lipid bilayer of the cell membrane is a fascinating organization of amphiphilic phospholipids. Natural and synthetic amphiphiles, such as antimicrobial peptides, interact with the cell membrane. Such interactions can impact transport of molecules across the cell membrane, disrupting cell functions. In this work, a library of tryptophan-containing amphiphiles was synthesized and their antimicrobial properties were explored.

First, a library of bis(tryptophan) amphiphiles was synthesized. Preparation included a coupling reaction of a diamine with tryptophan residues, via their carboxy-termini, at …

The Role Of Coagulase-Negative Staphylococcal Secreted Products On Staphylococcus Aureus And Staphylococcus Lugdunensis Infections, Denny Chin

Electronic Thesis and Dissertation Repository

The Staphylococcus genus is comprised of over 40 bacterial species. The most well-studied species in this genus is the notorious human pathogen Staphylococcus aureus, a bacterium that produces coagulase among many other virulence factors. Since S. aureus is a major health burden and causes a plethora of diseases in humans, it has received significant attention and much research has been done to understand its biology to treat diseases caused by this pathogen. However, the coagulase-negative staphylococci (CoNS) make up most of the staphylococcal species and have received less attention since they are thought to have a lesser impact on …

Development Of Soluble Bioactive Poly(Beta Amino Esters) (Pβaes) For Post-Synthesis Processing, Kelley Wiegman

Theses and Dissertations--Chemical and Materials Engineering

Polymers have proven to be a viable platform to facilitate the controlled and targeted release for a variety of therapeutic agents. Polymeric prodrugs are a growing area of drug delivery in which active pharmaceutical ingredients are covalently linked to a polymeric form in an effort to enhance stability, delivery, and pharmacology. One naturally occurring class of active ingredients, known as polyphenols, can potentially offer a vast array of beneficial therapeutic properties. However, the therapeutic efficacy of these compounds is severely limited due to poor solubility and bioavailability as well as an oxidative and thermal instability. To improve the efficacy of …

An Antimicrobial Polydopamine Surface Coating To Reduce Biofouling On Telemetry Tags Used In Marine Conservation Practices, Ariana Smies

Dissertations, Master's Theses and Master's Reports

Satellite telemetry tags are used to track the migration patterns of large cetaceans. These tags penetrate the dermis and remain embedded in the underlying blubber tissue. As the dermis of cetaceans is host to a diverse microbiome, and it is impossible to clean the skin before implanting the devices, the potential for infection is increased when the tags penetrate through the skin. H₂O₂ is a potential antimicrobial agent that, in addition to showing broad-spectrum efficacy against gram-negative and gram-positive bacteria, can promote wound healing outcomes by promoting proliferative factors and peptides that protect against oxidative stress. However, …

Rational Design Of Metal-Organic Frameworks (Mofs)-Based Functional Materials Towards Better Air Quality, Zan Zhu

Theses and Dissertations

Air pollution is a major threat to environmental safety and public health. Volatile organic compounds (VOCs), particulate matter (PM), and airborne microorganisms are three typical air pollutants. Conventional strategies to prevent and mitigate air pollution have been employed, which, however, are generally passive. For instance, VOC sensing through solid-state devices is a conventional approach, which, however, is not capable of capturing and removing VOCs. On the other hand, air filters and face masks are useful equipment to protect people from inhaling PM and airborne microorganisms. But most commercial filters can only capture them on the surfaces, which may cause secondary …

Genetic Characterization Of Antimicrobial Activities Of Endophytic Bacteria Burkholderia Strains Ms455 And Ms389, Jiayuan Jia

Theses and Dissertations

Strains MS455 and MS389, endophytic bacteria, were isolated from healthy soybean plant growing adjacent to a patch of plants affected by charcoal rot disease, caused by the fungal pathogen Macrophomina phaseolina. The complete genomes of both strains were sequenced and identified as Burkholderia species Strain MS455 exhibits broad-spectrum antifungal activities against economically important pathogens, including Aspergillus flavus. Random and site-specific mutations were employed in discovery of the genes that share high homology to the ocf gene cluster of Burkholderia contaminans strain MS14, which is responsible for production of the antifungal compound occidiofungin. RNA-seq analysis demonstrated ORF1, a …

Efficacy Of Selected Powdered Floor Treatments And Turmeric Rhizome Powder Against Salmonella, E. Coli, And L. Monocytogenes On Polyurethane-Concrete Flooring Material Carriers, Robert Sidney Fuller

Graduate Theses and Dissertations

The flooring in a food processing environment can become contaminated with pathogenic bacteria in many ways including foot and equipment traffic, incoming materials, and drain backups. Turmeric (Curcuma longa L.) rhizome powder and seventeen other commercially available powdered floor treatments with a variety of active ingredients including quaternary ammonium compounds (QAC), sodium percarbonate and similar perhydrates (SPC), urea, and borax, were investigated for reducing the levels of pathogens on flooring thereby reducing the risk of cross-contamination from the floor to food contact surfaces. Some of the commercially available floor treatments were Environmental Protection Agency (EPA) registered antimicrobials while others were …

Influencing The Inflammatory Response Through Multi-Scale Geometry, Antibiotic Release, And Fluid Management In A Textile-Based Biomaterial Wound Dressing, Elizabeth Gianino

All Dissertations

The total population of diagnosed and undiagnosed diabetes mellitus in the United states is expected to rise by 54% between the years of 2015 and 2030 contributing to $200 billion in health care expense. The exponential rise in common diabetic wounds, such as diabetic foot ulcers, puts a large population at risk for complications such as infection, amputation, and even death. Peripheral neuropathy leading to late diagnoses, patient non-compliance, and lack of holistic treatment options all contribute to complications with the incidence of new ulcer formation after treatment reaching 50%. This work explores the design, development, and in vitro evaluation …

Prevalence Of Salmonella, Campylobacter, And Spoilage Bacteria On Broiler Meat At Different Stages Of Commercial Poultry Processing, Hudson Thames

Theses and Dissertations

Salmonella and Campylobacter are two foodborne pathogens that continue to persist in broiler processing. Various studies have demonstrated that peracetic acid can effectively reduce the prevalence pathogens on broiler meat. However, there are a limited number of studies comparing the effects of peracetic acid on broiler meat from different processing plants. The objective of this study was to determine the prevalence of Salmonella, Campylobacter, and spoilage microbes on broiler meat at different stages of poultry processing in commercial plants that use peracetic acid as the primary antimicrobial. Results indicated that there was a high initial microbial presence on broiler meat …

Modulation Of Antibacterial Activity And Cytotoxicity In Amphipathic Cyclic Peptide [R4w4] Using Histidine Substitution, Ryan Stueber

Pharmaceutical Sciences (MS) Theses

Antibiotics have been the gold standard frontline defense against bacterial infections for decades. At the same time, these infecting bacteria have continued to evolve to resist developed antibiotics in an almost endless cycle. As such, we aim to take an alternative approach utilizing antimicrobial peptides (AMPs) as a means to end this cycle. [R4W4] is among known AMPs that demonstrated antimicrobial activity against methicillin-resistant staphylococcus aureus (MRSA) with a minimum inhibitory concentration (MIC) of 2.67 μg/mL. This peptide had notably effective antimicrobial activity, especially relative to linear (R4W4). However, it displayed a concerning level of cytotoxicity; eliciting a human embryonic …

Formulation Of Coffee Extract As Polymeric Nanoparticles And Studying Their Potential Biological Activities, Nouran Sharaf

Theses and Dissertations

Coffee extract was prepared and optimized (by solvent extraction) and subsequently entrapped into PLGA nanoparticles using single emulsion-solvent evaporation method (using Design Expert software). Dynamic Light Scattering, Scanning Electron Microscope, Fourier Transform-Infrared Spectroscopy and Folin Ciocalteau assay were used to characterize the NPs and to aid in selecting the optimum formulation conditions. The optimized NPs were in-vitro evaluated for their antimicrobial (by agar-well diffusion method), antioxidant (by DPPH assay) and anticancer (by MTT assay) activities. Finally, the release rate study was conducted for the NP sample showing the highly promising results.

The succeeded NP sample, in terms of the most …

Nanostructured Self-Assembled Thin Films Of Cationic Bottlebrush Block Copolymers, Hathaithep Senkum

Electronic Theses and Dissertations

Biofouling which is an accumulation of small species on submerged surfaces that causes detrimental impacts on economic and environmental factors for aquaculture activities and human health. To suppress the fouling, polymeric coatings from amphiphilic block copolymers provide nanostructured surfaces and carry multiple functional groups in a molecular chain. Polymers with quaternary ammonium functional groups enable material coatings to inhibit microbial adhesion by killing bacteria, consequently prolonging the material efficiency of, for example, medical implanted devices. Herein, well-defined architectures with full-arm density of quaternary ammonium bottlebrush polymers were generated from grafting-through ring opening metathesis polymerization (ROMP). Factors such as the halide …