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

Digital Commons Network

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

Engineering

PDF

Antimicrobial

Institution
Publication Year
Publication
Publication Type

Articles 1 - 30 of 42

Full-Text Articles in Entire DC Network

Uv-A Light: A Novel Method For Food Dehydration, Mckade S. Roberts May 2024

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 …


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 Oct 2023

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 …


Anaerobic Digestion Of Brewery Waste Including Spent Yeast And Hops, Dhanashree Rawalgaonkar Jun 2023

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 …


Nanoclays‑Containing Bio‑Based Packaging Materials: Properties, Applications, Safety, And Regulatory Issues, Kalpani Y. Perera, Maille Hopkins, Amit K. Jaiswal Dr, Swarna Jaiswal Feb 2023

Nanoclays‑Containing Bio‑Based Packaging Materials: Properties, Applications, Safety, And Regulatory Issues, Kalpani Y. Perera, Maille Hopkins, Amit K. Jaiswal Dr, Swarna Jaiswal

Articles

Food packaging is an important concept for consumer satisfaction and the increased shelf life of food products. The introduction of novel food packaging materials has become an emerging trend in recent years, which could be mainly due to environmental pollution caused by plastic packaging and to reduce food waste. Recently, numerous studies have been carried out on nanoclays or nanolayered silicate to be used in packaging material development as reinforcing filler composites. Different types of nanoclays have been used as food packaging materials, while montmorillonite (MMT), halloysite, bentonite (BT), Cloisite, and organically modified nanoclays have become of great interest. The …


Cross-Seeding Of Protegin-1 And Amyloid Beta To Inhibit Amyloid Beta Aggregation, Sarah Robinson Jan 2023

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 Jan 2023

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 …


Non-Antibiotic Antimicrobial Polydopamine Surface Coating To Prevent Stable Biofilm Formation On Satellite Telemetry Tags Used In Cetacean Conservation Applications, Ariana Smies, Jeremy Wales, Maureen Hennenfent, Laura Lyons, Caleigh R. Dunn, Jooke Robbins, Bruce Lee, Alexandre Zerbini, Rupak Rajachar Oct 2022

Non-Antibiotic Antimicrobial Polydopamine Surface Coating To Prevent Stable Biofilm Formation On Satellite Telemetry Tags Used In Cetacean Conservation Applications, Ariana Smies, Jeremy Wales, Maureen Hennenfent, Laura Lyons, Caleigh R. Dunn, Jooke Robbins, Bruce Lee, Alexandre Zerbini, Rupak Rajachar

Michigan Tech Publications

Satellite telemetry tags, used to monitor the migratory behavior of cetaceans, have the potential to be a vehicle for infection due to their invasive nature. Antibiotic coatings have been previously employed to reduce the chances of infection via the formation of a stable biofilm on the surface of the tags. However, increased use of antibiotics has the potential to lead to the development of antibiotic-resistant pathogens. To prevent the formation of antibiotic-resistant pathogens, a polydopamine surface coating that, when exposed to oxygen, releases low doses ( ~ 40-100 µ M ) of hydrogen peroxide over a prolonged period ( > 24 …


Land Use Influences The Composition And Antimicrobial Effects Of Propolis, Amara J. Orth, Emma H. Curran, Eric J. Haas, Andrew C. Kraemer, Audrey M. Anderson, Nicholas J. Mason, Carol A. Fassbinder-Orth Feb 2022

Land Use Influences The Composition And Antimicrobial Effects Of Propolis, Amara J. Orth, Emma H. Curran, Eric J. Haas, Andrew C. Kraemer, Audrey M. Anderson, Nicholas J. Mason, Carol A. Fassbinder-Orth

Department of Biological Systems Engineering: Papers and Publications

Honey bee propolis is a complex, resinous mixture created by bees using plant sources such as leaves, flowers, and bud exudates. This study characterized how cropland surrounding apiaries affects the chemical composition and antimicrobial effects of propolis. The chemical composition and compound abundance of the propolis samples were analyzed using Gas Chromatography- Mass Spectrometry (GC-MS) and the antimicrobial effects were analyzed using the 50% minimum inhibitory concentration (MIC50) assay against four relevant bee pathogens, Serratia marcescens, Paenibacillus larvae, Lysinibacillus sphaericus, and Klebsiella pneumoniae. Propolis composition varied significantly with apiary, and cropland coverage predicted mean sum abundance of …


Active Packaging Film Based On Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) Blends Incorporated With Tannic Acid And Gallic Acid For The Prolonged Shelf Life Of Cherry Tomato, Shubham Sharma, Kalpani Perera, Dileswar Pradhan, Brendan Duffy, Amit Jaiswal, Swarna Jaiswal Jan 2022

Active Packaging Film Based On Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) Blends Incorporated With Tannic Acid And Gallic Acid For The Prolonged Shelf Life Of Cherry Tomato, Shubham Sharma, Kalpani Perera, Dileswar Pradhan, Brendan Duffy, Amit Jaiswal, Swarna Jaiswal

Articles

The antimicrobial property is the key feature of active packaging. Biological macromolecules such as tannic and gallic acids are naturally found in plants such as tea, fruits, berries, and grapes. The incorporation of tannic acid (TA) and gallic acid (GA) in the biodegradable polymer blend Poly Lactide-Poly (Butylene Adipate-Co-Terephthalate) (PLA-PBAT) was used in this study to assess the potential of active packaging. TA and GA (10 wt%) composite films showed a 65%–66% increase in the UV barrier property. The tensile strength value increased after the incorporation of TA and GA (10 wt%), respectively. Overall, 1.67 and 2.2 log reductions in …


Encapsulation Of Essential Oils In Nanocarriers For Active Food Packaging, Shubham Sharma, Lilly Mulrey, Megan Byrne, Amit Jaiswal, Swarma Jaiswal Jan 2022

Encapsulation Of Essential Oils In Nanocarriers For Active Food Packaging, Shubham Sharma, Lilly Mulrey, Megan Byrne, Amit Jaiswal, Swarma Jaiswal

Articles

Active packaging improves a packaging system’s effectiveness by actively integrating additional components into the packaging material or the headspace around the packaging. Consumer demand and awareness have grown enough to replace chemical agents with natural active agents. Essential oils (EOs) are extensively distributed throughout nature but at low levels and sometimes with poor recovery yields, which poses an issue with their application in food. Due to the instability of EOs when added directly into a food product, they require encapsulation before being added to a packaging matrix such as liposomes, solid-lipid nanoparticles, nano-emulsions, cyclodextrins, and nanostructured lipid nano-carriers. This article …


Development Of Soluble Bioactive Poly(Beta Amino Esters) (Pβaes) For Post-Synthesis Processing, Kelley Wiegman Jan 2022

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 Jan 2022

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 Jan 2022

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 …


Influencing The Inflammatory Response Through Multi-Scale Geometry, Antibiotic Release, And Fluid Management In A Textile-Based Biomaterial Wound Dressing, Elizabeth Gianino Dec 2021

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 …


Nanostructured Self-Assembled Thin Films Of Cationic Bottlebrush Block Copolymers, Hathaithep Senkum May 2021

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 …


Catechol-Based Antimicrobial Polymers, Seyedehfatemeh Razaviamri, Kan Wang, Bo Liu, Bruce P. Lee Jan 2021

Catechol-Based Antimicrobial Polymers, Seyedehfatemeh Razaviamri, Kan Wang, Bo Liu, Bruce P. Lee

Michigan Tech Publications

Catechol is a key constituent in mussel adhesive proteins and is responsible for strong adhesive property and crosslinking formation. Plant-based polyphenols are also capable of chemical interactions similar to those of catechol and are inherently antimicrobial. This review reports a series of catechol-based antimicrobial polymers classified according to their antimicrobial mechanisms. Catechol is utilized as a surface anchoring group for adhering monomers and polymers of known antimicrobial properties onto various types of surfaces. Additionally, catechol's ability to form strong complexes with metal ions and nanoparticles was utilized to sequester these antimicrobial agents into coatings and polymer matrices. During catechol oxidation, …


Benzalkonium Chloride Alters Phenotypic And Genotypic Antibiotic Resistance Profiles In A Source Water Used For Drinking Water Treatment, Katherine R. Harrison, Anthony D. Kappell, Patrick J. Mcnamara Feb 2020

Benzalkonium Chloride Alters Phenotypic And Genotypic Antibiotic Resistance Profiles In A Source Water Used For Drinking Water Treatment, Katherine R. Harrison, Anthony D. Kappell, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Antibiotic resistance is a major public health concern. Triclosan is an antimicrobial compound with direct links to antibiotic resistance that was widely used in soaps in the U.S. until its ban by the U.S. Food and Drug Administration. Benzalkonium chloride (BAC), a quaternary ammonium compound, has widely replaced triclosan in soaps marketed as an antibacterial. BAC has been detected in surface waters and its presence will likely increase following increased use in soap products. The objective of this study was to determine the effect of BAC on relative abundance of antibiotic resistance in a bacterial community from a surface water …


Characterization Of Phenolic Acids For Incorporation Into Shape Memory Polymer Foams, Jingyi Liu Dec 2019

Characterization Of Phenolic Acids For Incorporation Into Shape Memory Polymer Foams, Jingyi Liu

Theses - ALL

Shape memory polymer (SMP) foams provide a promising new option for hemorrhage control on the battlefield; however, they lack a mechanism to control wound infections that can delay healing processes. Adding phenolic acids (PAs) into SMP foams provides a natural, non-drug option for incorporations of antioxidant and antimicrobial functionalities that may promote healing. However, PAs lack a systemic characterization of their structure/property relationships, and their chemical incorporation into SMP foams may alter their efficacy. In this work, a library of PAs was screened in terms of antioxidant and antimicrobial properties to provide a full understanding of how their structure affects …


Direct Patterning Of Nature-Inspired Surfaces For Biointerfacial Applications, Feyza Dundar Mar 2019

Direct Patterning Of Nature-Inspired Surfaces For Biointerfacial Applications, Feyza Dundar

Doctoral Dissertations

There are three major challenges for the design of patterned surfaces for biointerfacial applications: (i) durability of antibacterial/antifouling mechanisms, (ii) mechanical durability, and (iii) lifetime of the master mold for mass production of patterned surfaces. In this dissertation, we describe our contribution for the development of each of these challenges. The bioinspired surface, Sharklet AFTM, has been shown to reduce bacterial attachment via a biocide-free structure-property relationship effectively. Unfortunately, the effectiveness of polymer-based sharkskin surfaces is challenged over the long term by both eventual bacteria accumulation and a lack of mechanical durability. To address these common modes of …


Fabrication And Characterization Of Centrifugally Spun Poly(Acrylic Acid) Nanofibers, David De La Garza, Francisco De Santiago, Luis Materon, Mircea Chipara, Mataz Alcoutlabi Jan 2019

Fabrication And Characterization Of Centrifugally Spun Poly(Acrylic Acid) Nanofibers, David De La Garza, Francisco De Santiago, Luis Materon, Mircea Chipara, Mataz Alcoutlabi

Mechanical Engineering Faculty Publications and Presentations

The production of poly(acrylic acid) (PAA) nanofibers by the centrifugal spinning of PAA solutions in water is reported. The effect of the spinneret rotational speed and concentration of PAA solutions on the diameter of nanofibers and on their quality (assessed by the absence of beads) is discussed. The main physical properties of PAA such as glass-transition temperature (Tg) are studied in detail and compared to the feature of the as-received homopolymer. It is shown that the glass-transition temperature of the bulk PAA and PAA nanofibers (as measured by differential scanning calorimetry) depends on the heating rate according …


Rapid Fabrication Of Silver Nanoparticle/Polydopamine Functionalized Polyester Fibers, Yanfen Zhou, Liang Jiang, Ya Guo, Zhenhua Sun, Zhiqing Jiang, Shaojuan Chen, Jianwei Ma, Stephen Jerrams Jan 2019

Rapid Fabrication Of Silver Nanoparticle/Polydopamine Functionalized Polyester Fibers, Yanfen Zhou, Liang Jiang, Ya Guo, Zhenhua Sun, Zhiqing Jiang, Shaojuan Chen, Jianwei Ma, Stephen Jerrams

Articles

In this paper, silver nanoparticles functionalized poly(ethylene terephthalate) (PET) fibers with antimicrobial activity, electrical conductivity and good coating stability are reported. Firstly, silver plated PET fibers were fabricated by rapid polydopamine (PDA) modification followed by electroless plating. Secondly, the surface morphologies and compositions of PDA modified and silver coated PET fibers were characterized by employing scanning electron microscopy, atomic force microscopy, X-ray diffraction and energy dispersive spectrometry. Finally, the antimicrobial properties and electrical conductivity of the silver plated PET fibers were investigated. The results showed that the silver coated PET fibers exhibited excellent antimicrobial activity to both Escherichia coli and …


Metagenomics Reveal Triclosan-Induced Changes In The Antibiotic Resistome Of Anaerobic Digesters, M. Fujimoto, Daniel Elliott Carey, Patrick J. Mcnamara Oct 2018

Metagenomics Reveal Triclosan-Induced Changes In The Antibiotic Resistome Of Anaerobic Digesters, M. Fujimoto, Daniel Elliott Carey, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Triclosan (TCS) is a broad-spectrum antimicrobial used in a variety of consumer products. While it was recently banned from hand soaps in the US, it is still a key ingredient in a top-selling toothpaste. TCS is a hydrophobic micropollutant that is recalcitrant under anaerobic digestion thereby resulting in high TCS concentrations in biosolids. The objective of this study was to determine the impact of TCS on the antibiotic resistome and potential cross-protection in lab-scale anaerobic digesters using shotgun metagenomics. It was hypothesized that metagenomics would reveal selection for antibiotic resistance genes (ARGs) not previously found in pure culture studies or …


Thiol–Ene Photopolymerization: A Simple Route To Pro-Antimicrobial Networks Via Degradable Acetals (Pandas), William Martin May 2018

Thiol–Ene Photopolymerization: A Simple Route To Pro-Antimicrobial Networks Via Degradable Acetals (Pandas), William Martin

Honors Theses

The World Health Organization (WHO) has brought the growing epidemic of antibiotic resistance bacteria to the attention of the public and has expressed the need for the development of new methods of defense. In this direction, bioactive aldehyde essential oils have been shown to effectively act as antibiotic and antifungal agents. These bioactive compounds, when used in their pure form, are volatile and lack environmental stability. In this thesis, we describe the synthesis of pro-antimicrobial networks via degradable acetals (PANDAs) using thiol-ene photopolymerization. PANDAs were used as a new model for the high loading and release of bioactive aldehyde-containing compounds …


Antimicrobial Materials Via Thiol-Ene Chemistry, Dahlia Amato May 2018

Antimicrobial Materials Via Thiol-Ene Chemistry, Dahlia Amato

Dissertations

With the increasing prevalence of antimicrobial resistance, the escalation of opportunistic/pathogenic infections is a looming global crisis. To avoid the pitfalls of conventional antibiotics, this dissertation focuses on developing macromolecular solutions to develop novel antimicrobial materials based on essential oils (thymol, carvacrol, and aldehydes). It is well established that essential oil derivatives exhibit high potency towards a wide range of pathogenic microbes. The rapid photopolymerization kinetics, limited by-products, and homogeneous network formation afforded by thiol-ene photopolymerization are utilized to either encapsulate essential oil derivatives or convert them into monomers which can subsequently be incorporated into new antimicrobial materials with new …


Fractionation Of Lignin Derived Compounds From Thermochemically Processed Lignin Towards Antimicrobial Properties, Luke A. Dodge Jan 2018

Fractionation Of Lignin Derived Compounds From Thermochemically Processed Lignin Towards Antimicrobial Properties, Luke A. Dodge

Theses and Dissertations--Biosystems and Agricultural Engineering

The overuse of antibiotics in agriculture is an emerging concern, due to their potential detrimental impact to the environment. This study focuses on exploring antimicrobial properties of lignin derived compounds. Lignin is of interest as a feedstock to replacing some petroleum-based chemicals and products because it is the most abundant source of renewable aromatic compounds on the planet. Two lignin rich streams, residues from the enzymatic hydrolysis of dilute acid and alkaline pretreated corn stover, were decomposed via pyrolysis and hydrogenolysis, respectively. The resulting liquid oils were subjected to sequential extractions using a series of solvents with different polarities. Chemical …


Experiment-Based Quantitative Modeling For The Antibacterial Activity Of Silver Nanoparticles, Mohammad Aminul Haque Aug 2017

Experiment-Based Quantitative Modeling For The Antibacterial Activity Of Silver Nanoparticles, Mohammad Aminul Haque

Graduate Theses and Dissertations

Silver (Ag) has been well known for its antimicrobial activity for a long time. Recent research showed the potential of Ag nanoparticles as emerging antimicrobial agents. However, little quantitative analysis has been performed so far to decipher the mechanism of interaction between nanoparticles and bacteria. Here, a detailed analysis based on kinetic growth assay and colony forming unit assay has been carried out to study the antimicrobial effect of Ag nanoparticles against Escherichia coli (E. coli) bacteria. It was observed that the presence of Ag nanoparticles increased the lag time of bacterial growth while not affecting the maximum growth rate …


Stability And Interfacial Viscoelasticity Of Oil-Water Nanoemulsions Stabilized By Soy 2 Lecithin And Tween 20 For The Encapsulation Of Bioactive Carvacrol, Jerome J. Nash, Kendra Erk Dec 2016

Stability And Interfacial Viscoelasticity Of Oil-Water Nanoemulsions Stabilized By Soy 2 Lecithin And Tween 20 For The Encapsulation Of Bioactive Carvacrol, Jerome J. Nash, Kendra Erk

School of Materials Engineering Faculty Publications

The rheology of oil-in-water (O/W) droplet interfaces stabilized by food-grade emulsifiers (soy lecithin or Tween 20) under controlled aqueous conditions was investigated to elucidate its contribution in the kinetic stabilization of nanoemulsion-based delivery systems containing carvacrol, a naturally-derived antimicrobial compound. Dilational rheology of surfactant-laden O/W interfaces was measured using axisymmetric drop shape analysis. The kinetic stability of corresponding nanoemulsions (containing mixtures of carvacrol and medium-chain triglyceride (MCT) oil dispersed in water (pH 7)) was characterized using dynamic light scattering. Zwitterionic lecithin molecules adsorbed to the O/W interface for 24 h formed a notably viscoelastic layer, compared to nonionic Tween 20 …


Altered Antibiotic Tolerance In Anaerobic Digesters Acclimated To Triclosan Or Triclocarban, Daniel Elliott Carey, Patrick J. Mcnamara Nov 2016

Altered Antibiotic Tolerance In Anaerobic Digesters Acclimated To Triclosan Or Triclocarban, Daniel Elliott Carey, Patrick J. Mcnamara

Civil and Environmental Engineering Faculty Research and Publications

Bench-scale anaerobic digesters were amended to elevated steady-state concentrations of triclosan (850 mg/kg) and triclocarban (150 mg/kg) using a synthetic feed. After more than 9 solids retention time (SRT) values of acclimatization, biomass from each digester (and a control digester that received no antimicrobials) was used to assess the toxicity of three antibiotics. Methane production rate was measured as a surrogate for activity in microcosms that received doses of antibiotics ranging from no-antibiotic to inhibitory concentrations. Biomass amended with triclocarban was more sensitive to tetracycline compared to the control indicating synergistic inhibitory effects between this antibiotic and triclocarban. In contrast, …


Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman Jul 2016

Synthesis And Applications Of Non-Migratory Metal Chelating Active Packaging, Maxine J. Roman

Doctoral Dissertations

Many packaged foods use synthetic chelators (e.g. ethylenediaminetetraacetic acid, EDTA) to inhibit metal promoted oxidation and/or microbial growth that may cause food spoilage. Consumer demand for foods without synthetic additives has prompted growing interest in alternative preservation methods. Our research group has previously developed non-migratory metal chelating active packaging materials by surface immobilization of polymeric chelators and demonstrated their ability to inhibit lipid oxidation in model food emulsions. The work presented in this dissertation investigates the synthesis, performance stability, and practical application of metal chelating surface modifications to optimize design of non-migratory metal chelating active packaging materials. Metal chelating active …


Antimicrobial Effects Of Pine Essential Oil Against Listeria Monocytogenes, Elizabeth Louise Marhefka May 2015

Antimicrobial Effects Of Pine Essential Oil Against Listeria Monocytogenes, Elizabeth Louise Marhefka

Biological and Agricultural Engineering Undergraduate Honors Theses

Short leaf and loblolly pine were harvested in May 2014 and June 2014, respectively, at the University of Arkansas Monticello in Monticello, Arkansas. Short leaf and loblolly essential oils were prepared by hydrodistillation, using a Clevenger apparatus. Essential oils were extracted at separate times and showed different concentrations of the components α-pinene, β- pinene, 3-carene, limonene, and terpineol. Pine essential oil samples were tested through disc diffusion assay for antimicrobial activity against Listeria monocytogenes. This was done by placing ten μL of each essential oil sample on a paper disc on an agar plate that was inoculated with L. monocytogenes …