Life Sciences Commons^™

Postharvest Heat Treatments To Inhibit Penicillium Digitatum Growth And Maintain Quality Of Mandarin (Citrus Reticulata Blanco), Diana B. Queb-Gonzalez, Aurelio Lopez-Malo, María E. Sosa-Morales, Rossana Villa-Rojas

Department of Food Science and Technology: Faculty Publications

Use of fungicides is a common practice as a postharvest treatment to control fruit decay. Nowadays, environment-friendly technologies, such as heat treatments, are viable replacements. This study evaluated the effects of post-harvest heat treatments (traditional and microwave-assisted) on mandarins intentionally inoculated with Penicillium digitatum. For the studied heat treatments, the target temperature was 50C, which was held for 2.5 min. After heating, mandarins were cooled and stored at 25C for 13 days. MW treatments effectively prevented mold growth during storage, while HW only delayed it. Control mandarins (without treatment) showed the highest significant weight loss. Neither thermal treatment nor storage …

Incense Burning Is Associated With Human Oral Microbiota Composition, Yvonne Vallès, Claire K. Inman, Brandilyn A. Peters, Laila Abdel Wareth, Abdishakur Abdulle, Habiba Alsafar, Fatme Al Anouti, Ayesha Al Dhaheri, Divya Galani, Muna Haji, Aisha Al Hamiz, Ayesha Al Hosani, Mohammed Al Houqani, Abdulla Aljunaibi, Marina Kazim, Tomas Kirchhoff, Wael Al Mahmeed, Fatma Al Maskari, Abdullah Alnaeemi, Naima Oumeziane, Ravichandran Ramasamy, Ann Marie Schmidt, Henri Vallès, Eiman Al Zaabi, Scott Sherman, Raghib Ali, Jiyoung Ahn, Richard B. Hayes

All Works

© 2019, The Author(s). Incense burning is common worldwide and produces environmental toxicants that may influence health; however, biologic effects have been little studied. In 303 Emirati adults, we tested the hypothesis that incense use is linked to compositional changes in the oral microbiota that can be potentially significant for health. The oral microbiota was assessed by amplification of the bacterial 16S rRNA gene from mouthwash samples. Frequency of incense use was ascertained through a questionnaire and examined in relation to overall oral microbiota composition (PERMANOVA analysis), and to specific taxon abundances, by negative binomial generalized linear models. We found …

Exploring Secondary Structure In Bacteriophage Programmed Frameshift Elements, Samuel Okabayashi, Sean Mcclory

HON499 projects

Bacteriophages are viruses that infect bacteria and reproduce using host bacterial components. Part of the bacteriophage reproduction is assembly of the tail complex, which requires two assembly chaperone (TAC) proteins. In many phages the TAC’s are produced from a single gene through a non-canonical process called programmed translational frameshifting (PTF). The SEA-PHAGES program has produced hundreds of TAC genes that are accessible through phagesdb, a database of sequenced and annotated phage genomes. The sequences for the TAC gene were gathered from phagesdb and analyzed using ClustalOmega; a multiple sequence alignment (MSA) tool which revealed several positions where total conservation was …

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

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 cm2) were cut with …

A Research Of Some Pathogen Microorganisms In Traditional Sharri Cheese, Ali Aydin, Endra Luzha

UBT International Conference

Sharri cheese is a traditional hard, fatty and salty type of cheese produced in Sharri, Gora, Opoja and Shtirpca towns in the Sharr Mountains region. Sharri cheese is produced by processing sheep milk, cow milk or their mixture. The aim of this study was to determine the microbiological quality of traditionally and industrially produced Sharri cheese. In total 58 samples of cheese were examined. Staphyloccocus aureus was positive in 57 samples. In a research for Eschericia coli, 34 samples showed result from 1x10¹/mL to 4.5x10⁶/mL. According to our results, Sharri cheese can carry risk for foodborne pathogens and these …

Analyzing The Role Of A Protein Downregulated After Induction Of Filamentous Growth In Candida Albicans, Jazmine Vasquez, Ian Cleary, Derek P. Thomas

McNair Scholars Manuscripts

Candida albicans is a commensal fungus, normally living with its human host, however, it has the ability to cause invasive infection. Candida albicans is the fourth most frequent nosocomial infection affecting a vulnerable immunocompromised population. Candida albicans exhibits different morphologies including yeast, pseudohyphae, and hyphae. The varying morphological potential of this organism is a virulence trait. Because of this, research has focused on what drives activation of hyphal formation as well as what impedes it. During a filamentation assay, a novel observation pertaining to a subgroup of proteins being downregulated early after germination, was made. In this study, we constructed …

9th Annual Postdoctoral Science Symposium, University Of Texas Md Anderson Cancer Center Postdoctoral Association

Annual Postdoctoral Science Symposium Abstracts

The mission of the Annual Postdoctoral Science Symposium (APSS) is to provide a platform for talented postdoctoral fellows throughout the Texas Medical Center to present their work to a wider audience. The MD Anderson Postdoctoral Association convened its inaugural Annual Postdoctoral Science Symposium (APSS) on August 4, 2011.

The APSS provides a professional venue for postdoctoral scientists to develop, clarify, and refine their research as a result of formal reviews and critiques of faculty and other postdoctoral scientists. Additionally, attendees discuss current research on a broad range of subjects while promoting academic interactions and enrichment and developing new collaborations.

Comparison Of The Kinetic Parameters Of Escherichia Coli 0157:H7, Listeria Monocytogenes And Salmonella Typhimurium Derived From The Baranyi And Huang Models In A Chemically Defined Minimal Medium, Jose Isidro Fuentes

LSU Master's Theses

Microbial growth can be characterized by parameters such as lag time, growth rate, and maximum population density at any specific point of time. Mathematical models that predict microbial growth of foodborne pathogens are increasingly used in the food industry as a viable alternative to traditional methods of microbial enumeration. The Baranyi model has been widely used as the primary model of choice by many authors because of its performance and accuracy. The most recently developed Huang model has been less implemented and few comparisons between the Baranyi and Huang models have been made when modeling pathogenic growth. For this research, …

The Genesis Of Malaria: The Origin Of Mosquitoes And Their Protistan Cargo, Plasmodium Falciparum, Alan L. Gillen, Frank Sherwin

Alan L. Gillen

Malaria is caused by the parasite belonging to the genus Plasmodium; however, creation biologists maintain this organism was not always parasitic. Plasmodium is probably a degenerate form of algae. Mosquitoes, the vector of Plasmodium, were probably designed to be pollinators, not parasite vectors. In this article, we present both the evolutionary and creation explanation for the origin of malaria with a mention to its vector, the mosquito.

The purpose of this article is to provide a reasonable explanation for the genesis of malaria. Microbiology and parasitology research based on the creation paradigm appears to provide some answers to these puzzling …

Robert Koch, Creation, And The Specificity Of Germs, Alan L. Gillen, Douglas Oliver, Frank Sherwin

Alan L. Gillen

Microbiology is dominated by evolution today. Just look at any text, journal article, or the topics presented at professional scientific meetings. Darwin is dominant.

Microbiology is dominated by evolution today. Just look at any text, journal article, or the topics presented at professional scientific meetings. Darwin is dominant. Many argue that “nothing in biology makes sense except in the light of evolution” (Dobzhansky 1973). But it was not always this way. In fact, a review of the major founders of microbiology has shown that they were creationists.1 We would argue that a better idea thanevolution and one of much …

Darwin At The Drugstore? Testing The Biological Fitness Of Antibiotic Resistant Bacteria, Alan L. Gillen, Sarah Anderson

Alan L. Gillen

The issue of antibiotic resistance in bacteria is growing. For example, methicillin-resistant Staphylococcus aureus (MRSA) is a leading human pathogen. New strains of MRSA are resistant to methicillin and numerous other antibiotics, placing the patient in significant danger. Indeed, the Centers for Disease Control revealed in 2007 that the number of deaths due to MRSA exceeded that of AIDS in the United States. It is no wonder that antibiotic resistance is one of the most significant and important health care issues. The ability of bacterial pathogens to evade traditional antibiotics is faster than the drug makers’ ability to make new …

Oomycete Metabarcoding Reveals The Presence Of Lagenidium Spp. In Phytotelmata, Paula Leoro-Garzon, Andrew J. Gonedes, Isabel Olivera, Aurelien Tartar

Biology Faculty Articles

The oomycete genus Lagenidium, which includes the mosquito biocontrol agent L. giganteum, is composed of animal pathogens, yet is phylogenetically closely related to the well characterized plant pathogens Phytophthora and Pythium spp. These phylogenetic affinities were further supported by the identification of canonical oomycete effectors in the L. giganteum transcriptome, and suggested, mirroring the endophytic abilities demonstrated in entomopathogenic fungi, that L. giganteum may have similarly retained capacities to establish interactions with plant tissues. To test this hypothesis, culture-independent, metabarcoding analyses aimed at detecting L. giganteum in bromeliad phytotelmata (a proven mosquito breeding ground) microbiomes were performed. Two …

Electrostatically Localized Proton Bioenergetics: Better Understanding Membrane Potential, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

In Mitchell's chemiosmotic theory, membrane potential Δψ was given as the electric potential difference across the membrane. However, its physical origin for membrane potential Δψ was not well explained. Using the Lee proton electrostatic localization model with a newly formulated equation for protonic motive force (pmf) that takes electrostatically localized protons into account, membrane potential has now been better understood as the voltage difference contributed by the localized surface charge density ([H-⁺_L] + ⁿΣ _i=1 [M⁽ⁱ⁺⁾_L]) at the liquid-membrane interface as in an electrostatically localized protons/cations-membrane-anions capacitor. That is, the origin of membrane …

The Design Of The Mosquito And Its Dangers, Alan L. Gillen, Frank Sherwin

Alan L. Gillen

Mosquitoes (Family Culicidae) have been the scourge of mankind since the Fall. Although seemingly designed to inflict suffering and pain via rapid reproduction and formidable mouthparts, evidence mounts that this creature was not always the deadly vector it is today. Mosquitoes are currently and have always been pollinators. The majority of their lives they feed on plants, nectar, pollen, and microbes even in today's world. The Zika virus is but the latest of a significant list of pathogens spread by “the world’s most dangerous animal.” In the past, Christians have been involved in key discoveries linking mosquitoes to diseases.

A Rapid Viability And Drug‑Susceptibility Assay Utilizing Mycobacteriophage As An Indicator Of Drug Susceptibilities Of Anti‑Tb Drugs Against Mycobacterium Smegmatis Mc2 155, Gillian Catherine Crowley, Jim O'Mahony, Aidan Coffey, Riona G. Sayers, Paul D. Cotter

Department of Biological Sciences Publications

Background: A rapid in-house TM4 mycobacteriophage-based assay, to identify multidrug resistance against various anti-tuberculosis drugs, using the fast-growing Mycobacterium smegmatis mc² 155 in a microtiter plate format was evaluated, based on phage viability assays. Methods: A variety of parameters were optimized before the study including the minimum incubation time for the drugs, phage and M. smegmatis mc² 155 to be in contact. An increase in phage numbers over 2 h was indicative that M. smegmatis mc² 155 is resistant to the drugs under investigation, however when phage numbers remained static, M. smegmatis mc² 155 found to …

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

Graduate 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 …

Developing A Modern Microbiology Laboratory Manual To Enhance Student Learning, Alexander Yonchak

Senior Honors Projects

My project has been addressing the issue of incorporating recent developments in biosafety and pedagogical approaches for lab-courses into our existing educational curriculum by developing a new, modern lab manual aimed at improving experiential learning for introductory microbiology teaching labs. Through researching the most recent safety regulations, industry standards, & guidelines for such teaching labs, my manual clearly delineates learning outcomes to match the skills expected of undergraduates completing degrees within the life sciences. In addition, the lab manual that I have designed has been modernized to incorporate the most recent recommended safety precautions and is written in a user-friendly …

Characterization Of Developmental Genes In Streptomyces, Erin Orr

Undergraduate Distinction Papers

Characterization of two developmental genes in Streptomyces was carried out by different genetic manipulation techniques in two different species. The construction of an overexpression mutant for a gene encoding a putative c-di-GMP binding protein in Streptomyces scabies was started. This gene was found to be a homologue of a protein that was found to bind to c-di-GMP in a protein binding assay that consisted of streptavidin coated beads and biotinylated c-di-GMP. Attempts at cloning the gene encoding this protein into an overexpression construct were made. Another developmental gene was also investigated. Gene disruption by PCR targeting was used to isolate …

Searching For Megaviruses In Iceland, Delanie Baker

Student Symposium

The proposed Megavirales order comprises members of the previously known nucleocytoplasmic large DNA viruses (NCLDVs). Virus families in the Megavirales order include Poxviridae, Ascoviridae, and the recently explored families of megaviruses infecting free living amoeba such as Mimiviridae, Marseilleviridae, and Pandoraviridae. Megaviruses have been isolated from water and soil samples from Chile, France, India, and the United States. We chose to study the occurrence of megaviruses in Iceland because of the diverse habitats all within one island. No research has been carried out on the presence of megaviruses in Iceland. Samples of water and soil were collected from lava fields, …

A Comparative Analysis Of The Fermentation Capabilities Of Various Bifidobacterium Strains, Ella Oney

Honors Theses

Bifidobacterium is a genus of anaerobic bacteria that are commonly found to inhabit the gastrointestinal tract of many members of the animal kingdom. These microorganisms are adapted to obtain their carbon from the breakdown of complex carbohydrates. Marmosets, a mammal whose gut microbiome is inhabited by high levels of Bifidobacteria, consume gum Arabic as a major part of their diet. The purpose of this experiment is to determine whether Bifidobacterium strains isolated from the guts of marmosets are able to degrade and ferment this complex carbohydrate or one of its main constituents, arabinose. This was accomplished by inoculating isolates of …

Biogeochemical Characterization Of Metal Behavior From Novel Mussel Shell Bioreactor Sludge Residues, Sara C. Butler, James Pope, Subba Rao Chaganti, Daniel D. Heath, Christopher G. Weisener

Great Lakes Institute for Environmental Research Publications

Acid mine drainage (AMD) remediation commonly produces byproducts which must be stored or utilized to reduce the risk of further contamination. A mussel shell bioreactor has been implemented at a coal mine in New Zealand, which is an effective remediation option, although an accumulated sludge layer decreased efficiency which was then removed and requires storage. To understand associated risks related to storage or use of the AMD sludge material, a laboratory mesocosm study investigated the physio-chemical and biological influence in two conditions: anoxic storage (burial deep within a waste rock dump) or exposure to oxic environments (use of sludge on …

Genetic Study Of Checkpoint Defects Of The Mus81-1 Mutant In The Fission Yeast Schizosaccharomyces Pombe, Darlington Osei Abrefa

Browse all Theses and Dissertations

In response to various perturbations of DNA replication, the DNA replication checkpoint is activated in eukaryotes to stimulate a cascade of cellular responses that are crucial for maintaining genome stability and cell survival. Defects in the checkpoint pathway result in mutations and genome instability, which is a hallmark for cancers. This study used a genetic approach to identify a mutation in the MMS (methyl methanesulfonate) and UV-sensitive protein Mus81, a DNA repair enzyme that resolves aberrant DNA structures through the homologous recombination pathway. We show that a single missense mutation, identified in fission yeast mus81-1, causes moderate reduction in the …

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 …

The Role Of Cody In Hydrogen Peroxide Tolerance And Biofilm Formation Of Streptococcus Mutans, Kaitlin M. Rioux, Brandaliz Santiago-Narvaez

Honors Program Theses

Streptococcus mutans is the major cariogenic bacterium in the oral cavity. S. mutans causes disease by three main virulence factors: acid production, acid tolerance, and biofilm formation. S. mutans outcompetes various other species in the oral cavity, however it is affected by hydrogen peroxide production by these species. Based on previous findings and this research, hydrogen peroxide is shown to extend the lag phase of S. mutans but does not kill it unless present in extremely high amounts that are generally not produced by commensal species like S. sanguinis and S. gordonii in the oral cavity. CodY is a global …

Bacterioplankton Biogeography Of The Mississippi River Basin, Jason Taylor Payne

Electronic Theses and Dissertations

Bacterioplankton are important structural and functional components of river networks yet their biogeographical patterns in these systems are largely unknown. Using Illumina sequencing of the 16S rRNA gene we characterized variation in bacterioplankton community alpha diversity (within-sample richness of operational taxonomic units OTUs) and beta diversity (between-sample differences in composition) (1) along a 1 300-km downstream reach of the Mississippi River (2) over a range of temporal scales in the Lower Mississippi River (LMR) and (3) along cross-sectional transects repeated monthly for six months across the LMR floodplain. Particle-associated assemblages were richer in bacterial OTUs and more productive than free-living …

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 …

Characterization Of Wssf; A Putative Acetyltransferase From Achromobacter Insuavis And Pseudomonas Fluorescens, Cody Reese

Theses and Dissertations (Comprehensive)

Biofilms are a survival mechanism commonly employed by communities of bacteria for adherence and protection. Bacteria produce a matrix of polymers (e.g. exopolysaccharides, such as cellulose) that allow them to exert control on their local environment. In the case of cellulose biofilms, acetylation (addition of acetate on carbohydrates) is paramount for polymer integrity and in some cases virulence. For this research, the wrinkly spreader (WS) genotype of the emergent human pathogen Achromobacter insuavis facilitates infections of the eyes of contact lens wearers and the lungs of Cystic Fibrosis patients (CF). Chronic infections have created a growing concern for the protective …

Riparian Zone Soil Microbial Community Dynamics: Interactions With Nutrient Loadings, James Bannister

Theses and Dissertations (Comprehensive)

Riparian zones are a type of wetland described as the interface between land and a body of water such as a river or stream. Riparian zones are effective buffers against anthropogenic pollutants and nutrient loads from non-point sources that can greatly diminish water quality. Riparian zones can host a variety of plant species and associated microbial communities. The combined biological processes of plants, bacteria, and arbuscular mycorrhizal fungi (AMF) are key to nutrient cycling and nutrient removal in riparian zones. As such, understanding the factors that influence them is critical for watershed management. This research is targeted at obtaining a …