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Evaluating Mitochondrial Dynamics And Bioenergetics In Patient-Derived Human Induced Pluripotent Stem Cells And Differentiated Derivatives Modeling Leigh Syndrome, Fibi Meshrkey

Graduate Theses and Dissertations

Mitochondrial disorders are complex diseases that involve multiple systems and result from mutations and deletions in the mitochondrial genome. Leigh syndrome (LS) is a rare and devastating primary mitochondrial disorder characterized by progressive neuromuscular degeneration. Despite its severe consequences, the clinical genotype pathophysiological underlying LS remains elusive, posing significant challenges for the development of effective therapies. The current study aims to advance our understanding of the pathology and phenotype correlation of LS by evaluating mitochondrial dynamics and bioenergetics in patient-derived human induced pluripotent stem cells (hiPSCs) and their differentiated derivatives, which serve as a reliable model of the disease. Key …

Investigating And Characterizing Septin Cellular Regulators During Infection Related Development In M. Oryzae, Rinalda Proko

Graduate Theses and Dissertations

The fungus Magnaporthe oryzae causes a devastating disease of rice and wheat, called blast, which poses a major threat to food security across the planet. To enter plant tissue, M. oryzae produces a remarkable pressure-generating infection cell called an appressorium, which mechanically ruptures the tough cuticle of host leaves through the application of enormous physical force directed onto a narrow penetration structure emerging from its base. Importantly, appressorium form and functionality depends on the regulated assembly of a toroidal ring-like structure, composed of septins, which forms within its base. Septins are a family of membrane-associated GTP-binding proteins that polymerize into …

The Effect Of Sleep Deprivation On The Ability To Reappraise Negative Situations, Rebecca Campbell

Graduate Theses and Dissertations

Sleep and emotion regulation are important components of mental health and may function interdependently in the development and maintenance of mental health disorders. Unfortunately, there is limited experimental work on the impacts of sleep deprivation on reappraisal, a common emotion regulation strategy, in adults. Furthermore, increases in negative and decreases in positive affect are often associated with sleep loss. This study aimed to examine the relation between sleep deprivation and emotion regulation by asking adults to reappraise a series of vignettes before and after a randomly assigned night of sleep deprivation or normal sleep. Additionally, measures of self-reported emotion regulation …

Use Of Microorganisms For The Enrichment Of Zn And Se By Using Solid-State Fermentation, Rashmi Rangaswamaiah

Graduate Theses and Dissertations

Zinc (Zn) and selenium (Se) are essential minerals for human health and naturally found in many food sources. However, the risk of Zn and Se deficiency has been recognized in several countries. As most people throughout the world consume rice, grains, and cereals as staple foods in their daily diet, which contain a certain amount of phytic acid (antinutrients), the phytic acid content inhibits mineral absorption (Zn and Se) by the human body. Moreover, the low levels of Zn and Se content found in the crop's soil also reduce the amount of minerals in the food sources. Therefore, it is …

Unraveling The Biogenesis And Roles Of Iron-Sulfur Proteins During Nitrogen Fixation By Methanosarcina Acetivorans, Jasleen Saini

Graduate Theses and Dissertations

Iron-sulfur (Fe-S) clusters, the ancient cofactors found in proteins across all life forms, play vital roles in numerous cellular processes. Fe-S clusters exhibit structural diversity, ranging from simple to complex forms. Methanogens are anaerobic archaea that produce methane as a metabolic by-product through methanogenesis, a process dependent on numerous Fe-S proteins. Notably, methanogens are capable of fixing nitrogen (diazotrophy) facilitated by the enzyme complex called nitrogenase, which contains both simple and complex Fe-S clusters. While methanogens possess the largest number of Fe-S proteins, the factors involved in Fe-S cluster biogenesis remain largely unknown. Bacteria possess three distinct and well-characterized Fe-S …

Beef And Dairy Substitution Effects Associated With Carbon Labeling And An Information Intervention, Sara Gardner Hedgecock

Graduate Theses and Dissertations

Understanding consumer perceptions of carbon emissions in agriculture is a critical step to help increase the sustainability of food consumption. According to the Food and Agriculture Organization of the United Nations, 14.5 percent of all global anthropogenic GHG emissions are estimated to be represented by livestock (FAO), and cattle, raised for beef and milk, are the largest animal species responsible for emissions, comprising over 60 percent of the livestock sector’s emissions. This motivates this study’s analysis of beef and dairy milk products and alternatives. To better understand how consumers may substitute meat and milk products when provided with information about …

The Roles Of Estrogen Receptor Alpha-Interacting Rnas And Exosomes In Breast Cancer, And E-Cadherin In Carcinomas, Brihget Catalina Sicairos-Meza

Graduate Theses and Dissertations

Carcinomas are malignancies of epithelial cells and account for >80% of cancer-related deaths. Approximately 75% of breast cancers express estrogen receptor alpha (ERα). ERα promotes breast cancer progression by enhancing cancer cell proliferation. Tamoxifen is commonly used to treat ERα-positive breast cancers but can result in endocrine therapy resistance. The mechanisms underlying endocrine therapy resistance remain elusive. The Du lab recently found that ERα is an RNA-binding protein. However, the significance of the ERα-RNA interaction is unknown. We fractionated ERα-positive MCF7 cells into cytoplasmic and nuclear fractions, followed by immunoprecipitation of ERα with associated RNAs and RNA-sequencing. We identified many …

Screening A Set Of Tomato Genotypes For Resistance To Bacterial Wilt And A Genomic Wide Association Study And Genomic Prediction For Yield-Related Traits In ‘Lcp 85-384’. I. Sugarcane, Theresa Makawa Phiri

Graduate Theses and Dissertations

This thesis comprises two studies that focused on screening tomato genotypes for bacterial wilt resistance and a genome-wide association study and genomic prediction for yield-related traits in sugarcane with the aim of contributing to the breeding programs. In the first chapter, 40 tomato accessions from the USDA collection were evaluated for their resistance to Ralstonia solanacearum isolate P822 under controlled greenhouse conditions. The plants were inoculated, and disease symptoms were visually assessed. Disease severity was rated on a scale of 0 to 4, where 0 represented no wilting and 4 indicated complete leaf wilting. Among the tested accessions, five (PI …

Short-Term Response In Soil Health To Management Practices Within Large- And Small-Scale Cropping Systems In Arkansas, Torri Holder

Graduate Theses and Dissertations

Improving soil health is a growing area of interest within large- and small-scale agricultural systems in Arkansas as producers face increasing input costs, increased awareness of variability and intensity in extreme weather events, decreasing resource availability, and suboptimal productivity related to environmental degradation. Practices aimed at improving soil health such as cover cropping and the use of organic amendments are increasingly recommended and adopted; however, research on optimal management in the Mid-South is lacking. Two studies were conducted to evaluate the effectiveness of soil health management under both small- and large-scale farming operations in Arkansas. The objective of the small-scale …

Chemostratigraphic And Paleoclimatic Studies Of Cloverly Formation, Northern Wyoming, U.S.A, Queen Amarachi Kalu

Graduate Theses and Dissertations

The Early – Late Cretaceous transition in Western North America recorded a period of rapid climatic and tectonic change in Earth’s history. Major climate events associated with large igneous province eruptions caused several instances of ocean anoxic events (OAE) and perturbations to the global carbon (C) – cycle. These perturbations to the global C-cycle are observed in the bulk organic C record of both marine and terrestrial deposits and can be used to correlate units across major depositional basins. Major efforts are being made to generate time-constrained palaeontologic and paleoclimate information from the North American Cordilleran foreland basin and C-isotope …

Investigation Of Consumer Freezing Practices, Condition And Duration On Palatability Of Beef, Elizabeth Sue Neal

Graduate Theses and Dissertations

The objective of these studies was to determine: the impact of extended periods of frozen storage duration and packaging type on palatability traits of cooked beef steaks from two muscles and the impact of freezing type and storage duration on objective and subjective measures of ground beef palatability traits. In study 1, no differences were elicited from any of the possible interactions (P= 0.95) for SSF or CL: package × muscle × freezing duration, package × muscle, package × duration or muscle × duration. However, freezing duration did impact both SSF (P < 0.01) and CL (P < 0.001). Generally, for both SSF and CL steaks that were frozen for 9-months elicited both the highest SSF values as well as the greatest percentage of CL among all treatments. In comparison, EM was impacted by the interaction (P = 0.059) of packaging type  muscle  freezing duration. Samples from OW GM stored for 9-months elicited the highest percentage of EM while fresh OW LL samples resulted in the lowest. Additionally, expressible moisture was impacted by the interaction (P = 0.047) of muscle  freezing duration. Among all treatments, GM steaks that were frozen for 9-months elicited the highest EM values and fresh LL samples the lowest EM values. Contrastingly, there was no significant difference observed in expressible moisture for the interaction (P  0.18) of package type  freezing duration or for the interaction (P = 0.70) of package type  muscle. Generally, fresh OW GM steaks resulted in the greatest concentration of lipid derived volatile compounds such as aldehydes, hydrocarbons and alcohols which contrasted sensory ratings of trained panelists that indicated oxidized and refrigerator-stale ratings increased as storage time increased for OW steaks. In study 2, The interaction of freezer treatment × storage duration impacted gumminess (P = 0.05), a TPA attribute. In greater detail, samples stored in RF for 6-months resulted in the greatest gumminess values (P < 0.001), while those stored in the CF for 12-months elicited the lowest (P < 0.001). Similarly, flavor development was also impacted by the interaction (P = 0.05) of freezer treatment × storage duration. Three lipid derived compounds were of greatest concentration among RF patties stored for 1-month. In contrast, the interaction of freezer treatment × storage duration elicited no impact on consumer ratings, SF or TBARS. Nonetheless, frozen storage duration impacted TPA, flavor development, consumer ratings, SF and TBARS as a main effect (P < 0.05), especially in regard to tenderness and juiciness. Moreover, beef flavor development, tenderness and juiciness are impacted by freezing duration, muscle, freezer type and packaging, however these factors are not necessarily independent of one another. Furthermore, the retail display period is a critical period for fresh beef steaks, especially when packaged in aerobic conditions. For optimal eating experience, beef products should be stored for extended periods in a vacuum packaging, in a designated freezer that is not opened frequently to allow for optimal air flow regulation and minimize freezer burn to improve tenderness and juiciness.

Generating Health-Promoting Bioactive Compounds And Nanoporous Materials From Rice Processing Byproducts Via Supercritical Carbon Dioxide Technology, Sumanjot Kaur

Graduate Theses and Dissertations

Rice husk and bran, byproducts of rice processing, are generated in large quantities (~30-40% of the total rice weight) and are discarded as waste or burned in an open field, creating a major disposal problem for the rice industry. However, these byproducts contain high-value compounds, including phytochemicals, fiber, and proteins. Therefore, the goal of this study was to generate high-value food ingredients from rice processing byproducts using a green, innovative approach based on supercritical carbon dioxide (SC-CO2) technology. Specific objectives were to (i) extract health-promoting phytochemicals from rice husk and (ii) convert rice bran into nanoporous materials using SC-CO2. First, …

Runoff Water Quality And Crop Growth As Affected By Wastewater-Derived Struvite, Machaela Morrison

Graduate Theses and Dissertations

Mined phosphate rock, used to produce phosphorus (P) fertilizers, is a finite resource. Struvite (MgNH4PO4 • 6H2O) that has been synthetically produced from a stock solution of known P and nitrogen (N) concentrations has been shown to be an effective, alternative fertilizer-P source for various crops. However, little is known about the runoff-water-quality implications from and the crop response to soil application of struvite created from an actual municipal wastewater source. This study consisted of two objectives: i) to evaluate the effects of soil [i.e., Creldon (Oxyaquic Fragiudalf), Dapue (Fluventic Hapludoll), Roxana (Typic Udifluvent), and Calloway (Aquic Fraglossudalf) series], fertilizer-P …

On Neo-Humean Accounts For Natural Laws, Tori Helen Cotton

Graduate Theses and Dissertations

Humeanism about laws is a metaphysical doctrine that claims that the complete scope of the world is comprised of the mosaic—a vast collection of particular, localized facts about the world, and everything else supervenes on this arrangement of facts. Reductionism about laws, the claim that laws of nature reduce to, and thereby supervene on, the Humean mosaic, follows from this view. The first part of the thesis explores Humeanism about laws and the evolving landscape of pragmatic approaches within this domain. Building upon the insights gained from this analysis, the second part of the thesis proposes a novel response to …

Evaluation Of Biochar Rate And Hemp Cultivar For The Phytoremediation Of Heavy-Metal-Contaminated Soil From The Tar Creek Superfund Site, Dietrich Thurston

Graduate Theses and Dissertations

Soil contamination by cadmium (Cd), lead (Pb), and zinc (Zn) at the Tar Creek Superfund site in Northeast Oklahoma remains a threat to the environment and local ecosystem. Phytoremediation by industrial hemp (Cannabis sativa L.) and the use of biochar (BC) have been independently shown to be effective methods to remediate heavy-metal-contaminated soils. The objective of this greenhouse study was to evaluate the effects of industrial hemp cultivar (‘Carmagnola’ and ‘Jinma’), BC rate (0, 2, 5, and 10% by volume), soil contamination level (low, medium, and high), and their interactions on above- and belowground (AG and BG, respectively) plant dry …

Nutrient Responses To Hippuric Acid In Sheep Urine Applied To Pasture Soil Cores, Ethan Avery Collins

Graduate Theses and Dissertations

Hippuric acid is a breakdown product of tannins, which bind with proteins in the animal rumen and slow down protein metabolism, thus increasing nitrogen (N) retention in the animal. Increased hippuric acid concentration in bovine and ovine urine applied to soil may decrease rates of nitrification, denitrification, and nitrous oxide fluxes in pasture soils. Additionally, condensed tannins have increased rates of carbon mineralization when incorporated in humus and leaf litter. To evaluate effects of hippuric acid concentration, treatments of urine from sheep fed a tannin-supplemented diet, synthetic urine, or urea controls were applied to intact soil cores seeded with crabgrass …

Liquid Crystalline Coacervates Composed Of Chromonic Mesogens And Polyelectrolytes, Elizabeth Adeogun

Graduate Theses and Dissertations

Complex coacervates are formed by liquid-liquid phase separation of an aqueous solution of oppositely charged ions. Although several mixtures of molecules of natural and synthetic macro-ion have been shown to form complex coacervates, the formation of liquid crystalline (LC) coacervates are sparsely reported. LC coacervates have a unique property in that they can change their shape and optical property in response to external stimuli such as changes in temperature, pH, or the presence of specific molecules. This property makes LC coacervates useful as a sensor, as they can be engineered to respond to specific stimuli and generate a measurable signal …

A Pilot Study Of Students’ Ethical Decision Making And Emotional Intelligence, Casandra K. Cox

Graduate Theses and Dissertations

Demand for ethical leaders in agriculture is high to meet 21st century goals, while ethics course offerings in land-grant institutions are limited. The purpose of this case study was to establish a baseline of current University of Arkansas Bumpers College of Agriculture, Food and Life Science (Bumpers College) agriculture and natural resource program students’ ethical decision making (EDM), as measured by the DIT-2, and emotional intelligence (EI), as measured by STEM-B and STEU-B, determine if EI mean scores predict EDM, and identify relationships between EDM or EI and demographic characteristics or lifespan experiences. An online survey design with probability sampling …

Effects Of Supplemental Trace Minerals As Amino Acid Complexed Or Inorganic Sources For Beef Cattle From Receiving Through Finishing, Robin Ashley Cheek

Graduate Theses and Dissertations

The objective of experiments was to investigate the effects of inorganic or amino acid-complexed sources of trace minerals on health, gain performance, liver mineral concentrations, and carcass characteristics of beef heifers from receiving through finishing. To investigate the effects of inorganic or amino acid-complexed sources of trace minerals (zinc, copper, manganese, and cobalt) on performance and morbidity of beef heifers during the receiving period, crossbred beef heifer calves arriving on 3 delivery dates were used in a 42-day receiving trial. Treatments consisted of supplemental zinc (360 mg/d), copper (125 mg/d), manganese (200 mg/d), and cobalt (12 mg/d) from complexed (Availa-4, …

Understanding The Environmental And Genetic Influence On Fluctuating Asymmetry And Developmental Instability In Primates, Ashly N. Romero

Graduate Theses and Dissertations

This dissertation explored the impact of environmental factors on the development and perpetuation of fluctuating asymmetry (FA) and sought to understand the role evolution may play in the FA exhibited in two primate populations: the free-ranging Cayo Santiago rhesus macaques (Macaca mulatta) and the Southwest National Primate Research Center olive baboons (Papio hamadryas anubis). Demographic, ontogenetic, secular, external, and genetic factors were examined. Specifically, this dissertation investigated FA over all ontogenetic stages, across decades, between sexes, in association with ecological catastrophes, and with tooth pathology to try and tease apart factors that may influence FA and developmental instability. This dissertation …

Assessing The Effects Of A Mixed Eimeria Spp. Challenge On Performance, Intestinal Integrity, And The Gut Microbiome Of Broiler Chickens, Danielle Graham, Victor Petrone-Garcia, Xochitl Hernandez-Velasco, Makenly E. Coles, Marco A. Juarez-Estrada, Juan D. Latorre, Jianmin Chai, Stephanie Shouse, Jiangchao Zhao, Aaron Forga, Roberto Señas-Cuesta, Lauren Laverty, Kristen Martin, Carolina Trujillo-Peralta, Ileana Loeza, Latasha Gray, Billy M. Hargis, Guillermo Tellez-Isaias

Poultry Science Faculty Publications and Presentations

A mixed Eimeria spp. challenge model was designed to assess the effects of challenge on broiler chicken performance, intestinal integrity, and the gut microbiome for future use to evaluate alternative strategies for controlling coccidiosis in broiler chickens. The experimental design involved broiler chickens divided into two groups: a control group (uninfected) and a positive control group, infected with Eimeria acervulina (EA), Eimeria maxima (EM), and Eimeria tenella (ET). At day-of-hatch, 240 off-sex male broiler chicks were randomized and allocated to one of two treatment groups. The treatment groups included: (1) Non-challenged (NC, n = 5 replicate pens); and (2) challenged …

Occupancy And Activity Patterns Of Nine-Banded Armadillos (Dasypus Novemcinctus) In A Suburban Environment, Brett Degregorio, Matthew R. Mcelroy, Emily P. Johansson

Biological Sciences Faculty Publications and Presentations

The geographic range of the nine-banded armadillo (Dasypus novemcinctus) has rapidly been expanding within the United States for the last 150 years. One of the factors contributing to this astounding range expansion is the species’ ability to survive in and colonize human-dominated areas. Despite the fact that armadillos live alongside humans in numerous towns and cities across the Southeastern, Southcentral, and now Midwestern United States, we know relatively little about the behavior and ecology of armadillos in human-developed areas. Here, we used motion-triggered game cameras in over 115 residential yards in the rapidly developing Northwest corner of Arkansas …

The Effect Of Herbal Adaptogen On Feeding-Related Hypothalamic Neuropeptides In Heat-Stressed Broilers, Maryam Afkhami Ardakani

Graduate Theses and Dissertations

Heat stress is a major issue in the poultry industry, having numerous negative consequences for chicken productivity. Decreasing feed intake is one of these issues, which results in higher mortality and poor growth performance. Moreover, Herbal adaptogens, plant extracts that are also known as stress response modifiers, are metabolic regulators that improve an organism's ability to adapt to environmental stresses and minimize damage from such stressors. Previously, we published data indicating that herbal adaptogen supplementation increased feed intake under heat stress conditions. Therefore, we hypothesized that dietary herbal adaptogen supplementation might exert these effects through alteration of the expression of …

Editorial: High-Impact Respiratory Rna Virus Diseases, Victor Manuel Patrone-García, Inkar Castellanos-Huerta, Guillermo Tellez-Isaias

Poultry Science Faculty Publications and Presentations

Editorial on the Research Topic

High-impact respiratory RNA virus diseases

Striped Expression Of Leucine-Rich Repeat Proteins Coordinates Cell Intercalation And Compartment Boundary Formation In The Early Drosophila Embryo, Chloe A. Kuebler, Adam C. Pare

Biological Sciences Faculty Publications and Presentations

Planar polarity is a commonly observed phenomenon in which proteins display a consistent asymmetry in their subcellular localization or activity across the plane of a tissue. During animal development, planar polarity is a fundamental mechanism for coordinating the behaviors of groups of cells to achieve anisotropic tissue remodeling, growth, and organization. Therefore, a primary focus of developmental biology research has been to understand the molecular mechanisms underlying planar polarity in a variety of systems to identify conserved principles of tissue organization. In the early Drosophila embryo, the germband neuroectoderm epithelium rapidly doubles in length along the anterior-posterior axis through a …

In Vitro And In Vivo Evaluation Of Chlorhexidine Salts As Potential Alternatives To Potassium Dichromate For Eimeria Maxima M6 Oocyst Preservation, Lauren Laverty, Lesleigh C. Beer, Kristen Martin, Xochitl Hernandez-Velasco, Marco A. Juarez-Estrada, Marcela Arango-Cardona, Aaron Forga, Makenly E. Coles, Christine N. Vuong, Juan D. Latorre, Roberto Señas-Cuesta, Ileana Loeza, Latasha Gray, John R. Barta, Billy M. Hargis, Guillermo Tellez-Isaias, Brittany D. Graham

Poultry Science Faculty Publications and Presentations

Introduction: Coccidiosis caused by the Eimeria spp., an Apicomplexan protozoon, is a major intestinal disease that affects the poultry industry. Although most cases of coccidiosis are subclinical, Eimeria infections impair bird health and decrease overall performance, which can result in compromised welfare and major economic losses. Viable sporulated Eimeria oocysts are required for challenge studies and live coccidiosis vaccines. Potassium dichromate (PDC) is typically used as a preservative for these stocks during storage. Although effective and inexpensive, PDC is also toxic and carcinogenic. Chlorhexidine (CHX) salts may be a possible alternative, as this is a widely used disinfectant with less …

Likelihood-Based Tests Of Species Tree Hypotheses, Richard Adams, Michael Degiorgio

Entomology and Plant Pathology Faculty Publications and Presentations

Likelihood-based tests of phylogenetic trees are a foundation of modern systematics. Over the past decade, an enormous wealth and diversity of model-based approaches have been developed for phylogenetic inference of both gene trees and species trees. However, while many techniques exist for conducting formal likelihood-based tests of gene trees, such frameworks are comparatively underdeveloped and underutilized for testing species tree hypotheses. To date, widely used tests of tree topology are designed to assess the fit of classical models of molecular sequence data and individual gene trees and thus are not readily applicable to the problem of species tree inference. To …

Er Translocon Inhibitor Ipomoeassin F Inhibits Triple-Negative Breast Cancer Growth Via Blocking Er Molecular Chaperones, Shishi Tao, Eun Ju Yang, Guanghui Zong, Pui Kei Mou, Guowen Ren, Liang Chen, Ho Jeong Kwon, Jianhong Zhou, Zhijian Hu, Arman Khosravi, Qingyang Zhang, Yuchun Du, Wei Q. Shi, Joong Sup Shim

Biological Sciences Faculty Publications and Presentations

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer where no effective therapy has been developed. Here, we report that the natural product ER translocon inhibitor ipomoeassin F is a selective inhibitor of TNBC cell growth. A proteomic analysis of TNBC cells revealed that ipomoeassin F significantly reduced the levels of ER molecular chaperones, including PDIA6 and PDIA4, and induced ER stress, unfolded protein response (UPR) and autophagy in TNBC cells. Mechanistically, ipomoeassin F, as an inhibitor of Sec61α-containing ER translocon, blocks ER translocation of PDIA6, inducing its proteasomal degradation. Silencing of PDIA6 or PDIA4 by RNA interferences …

Horizontal Transfer Of Probable Chicken-Pathogenicity Chromosomal Islands Between Staphylococcus Aureus And Staphylococcus Agnetis, Douglas D. Rhoads, Jeff Pummil, Nnamdi S. Ekesi, Adnan A.K. Alrubaye

Cell and Molecular Biology Faculty Publications and Presentations

Staphylococcus agnetis is an emerging pathogen in chickens but has been most commonly isolated from sub-clinical mastitis in bovines. Previous whole-genome analyses for known virulence genes failed to identify determinants for the switch from mild ductal infections in cattle to severe infections in poultry. We now report identification of a family of 15 kbp, 17–19 gene mobile genetic elements (MGEs) specific to chicken osteomyelitis and dermatitis isolates of S. agnetis. These MGEs can be present in multiple copies per genome. The MGE has been vectored on a Staphylococcus phage that separately lysogenized two S. agnetis osteomyelitis strains. …

Silver Ions Inhibit Bacterial Movement And Stall Flagellar Motor, Benjamin Russell, Ariel Rogers, Ryan Yoder, Matthew Kurilich, Venkata Rao Krishnamurthi, Jingy Chen, Yong Wang

Physics Faculty Publications and Presentations

Silver (Ag) in different forms has been gaining broad attention due to its antimicrobial activities and the increasing resistance of bacteria to commonly prescribed antibiotics. However, various aspects of the antimicrobial mechanism of Ag have not been understood, including how Ag affects bacterial motility, a factor intimately related to bacterial virulence. Here, we report our study on how Ag⁺ ions affect the motility of E. coli bacteria using swimming, tethering, and rotation assays. We observed that the bacteria slowed down dramatically by >70% when subjected to Ag⁺ ions, providing direct evidence that Ag⁺ ions inhibit the motility …