Environmental Microbiology and Microbial Ecology Commons^™

Comparing Capabilities Of Shewanella Oneidensis Mr-1 And The Microbial Community Of Iron Caves To Reduce Fe(Iii), Aaron Douglas Pham

Williams Honors College, Honors Research Projects

Caves are generally formed by the erosion and/or dissolution of rock and its subsequent removal by water. Iron ore caves (IOCs) form despite being hosted by relatively insoluble and weathering-resistant rock. Due to the discovery of a microbial community behind the walls of these caves, it was hypothesized that these bacteria could be responsible for speleogenesis. Iron ore exists in an oxidized (Fe(III)) state, but reduced (Fe(II)) form is soluble. It was further reasoned that the bacteria might be able to reduce Fe(III) through direct metabolic activity, which uses iron as an electron acceptor. Here we show that cave microorganisms …

Molecular Detection Of Host-Specific Fecal Bacteria In Three Major Watersheds Of Piedmont Georgia, Muhammad Amar

Biology Theses

Abstract

Fecal pollution is a major concern in creeks and rivers. The aim of this study was to enumerate fecal coliform bacteria and identify the source of contamination using Microbial Source Tracking at three different creeks (Mountain Oak, Long Cane, and Ulcohatchee) in the Piedmont region of Georgia. Data collected in this research will be used to formulate watershed rehabilitation plans to decrease the transfer of fecal indicator bacteria (FIB) into these creeks. Samples were collected at several sites along the creeks (4 sites at Mountain Oak, 10 sites at Long Cane, and 5 sites at Ulcohatchee). The site locations …

Aspergillus Niger Decreases Bioavailability Of Arsenic(V) Via Biotransformation Of Manganese Oxide Into Biogenic Oxalate Minerals, Bence Farkas, Marek Kolenčík, Miroslav Hain, Edmund Dobročka, Gabriela Kratošová, Marek Bujdoš, Huan Feng, Yang Deng, Qian Yu, Ramakanth Illa, B. Ratna Sunil, Hyunjung Kim, Peter Matúš, Martin Urík

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The aim of this work was to evaluate the transformation of manganese oxide (hausmannite) by microscopic filamentous fungus Aspergillus niger and the effects of the transformation on mobility and bioavailability of arsenic. Our results showed that the A. niger strain CBS 140837 greatly affected the stability of hausmannite and induced its transformation into biogenic crystals of manganese oxalates—falottaite and lindbergite. The transformation was enabled by fungal acidolysis of hausmannite and subsequent release of manganese ions into the culture medium. While almost 45% of manganese was bioextracted, the arsenic content in manganese precipitates increased throughout the 25-day static cultivation of fungus. …

Analysis And Exploration Of Novel Antibiotic-Producing Streptomyces Spp. In Spokane County, Washington, Kyle S. Kramer, Jenifer B. Walke Ph.D

2020 Symposium Posters

According to the Centers for Disease Control and Prevention, a US citizen is infected by an antibiotic-resistant pathogen every 11 seconds, and every 15 minutes, a patient dies as a result of these infections. Due to the increasing incidence of antibiotic-resistant pathogenic microbes, the study and exploration of novel antibiotics from novel environments are imperative as infectious diseases are the second leading cause of death in the United States. The purpose of this research is to investigate and analyze antibiotic-producing soil microbes in Spokane County, WA, with hopes of discovering novel antibiotic-producing microbes, specifically Streptomyces species, and explore some of …

Antibiotic Resistant Bacteria, Antibiotic Resistance Genes And Potential Drivers In The Aquatic Environments, Shuo Shen

Dissertations

As antibiotic resistance genes in aquatic environment have been increasing across the world, affecting water quality and public health, many studies documented concentrations of antibiotic resistance genes and some studies discussed their potential drivers. However, systematic and quantitative reviews that link antibiotic resistance genes (ARGs) to anthropogenic and environmental factors are limited. Nevertheless, this information will be important for developing regulation policy on controlling antibiotic use and therefore reducing potential risks to antibiotic resistance. I conducted meta-analysis of ARGs concentration at a global scale using Bayesian inference to explore climatic and socio-economic factors as drivers. I found local-scale climatic variables …

Investigation Of An Elevational Gradient Reveals Strong Differences Between Bacterial And Eukaryotic Communities Coinhabiting Nepenthes Phytotelmata, Kadeem J. Gilbert, Leonora S. Bittleston, Mark Arcebal K. Naive, Anthony E. Kiszewski, Perry Archival C. Buenavente, David J. Lohman, Naomi E. Pierce

Publications and Research

Elevation is an important determinant of ecological community composition. It integrates several abiotic features and leads to strong, repeatable patterns of community structure, including changes in the abundance and richness of numerous taxa. However, the influence of elevational gradients on microbes is understudied relative to plants and animals. To compare the influence of elevation on multiple taxa simultaneously, we sampled phytotelm communities within a tropical pitcher plant (Nepenthes mindanaoensis) along a gradient from 400 to 1200 m a.s.l. We use a combination of metabarcoding and physical counts to assess diversity and richness of bacteria, micro-eukaryotes, and arthropods, and compare the …

Identification Of Antibiotic Producing Soil Bacteria Against Bacillus Subtilis, Morgan Brockhouse, Dr. Lori Scott

Identifying and Characterizing Novel Antibiotic Producing Microbes From the Soil

This project is a collaboration with the Tiny Earth Project Initiative (TEPI), which is a global network of educators and students focused on student-sourcing antibiotic discovery from soil. Individual strains of soil bacteria were isolated and produced antibiotic against Bacillus subtilis. Two of these samples were sequenced using the 16S rRNA gene to reveal they are very closely related to the genus Pseudomonas.

Biogeographic Study Of Human Gut-Associated Crassphage Suggests Impacts From Industrialization And Recent Expansion, Tanvi P/ Honap, Krithivasan Sankaranarayanan, Stephanie L. Schnorr, Andrew T. Ozga, Christina Warinner, Cecil M. Lewis Jr.

Anthropology Faculty Research

CrAssphage (cross-assembly phage) is a bacteriophage that was first discovered in human gut metagenomic data. CrAssphage belongs to a diverse family of crAss-like bacteriophages thought to infect gut commensal bacteria belonging to Bacteroides species. However, not much is known about the biogeography of crAssphage and whether certain strains are associated with specific human populations. In this study, we screened publicly available human gut metagenomic data from 3,341 samples for the presence of crAssphage sensu stricto (NC_024711.1). We found that crAssphage prevalence is low in traditional, hunter-gatherer populations, such as the Hadza from Tanzania and Matses from Peru, as compared to …

The Effects Of Staining Cyanobacteria With Sytoxgreen After Lysis By Freeze-Thaw And Lysis By Ethanol, Samantha Galambos

Williams Honors College, Honors Research Projects

The purpose of this project is to find the effects of staining toxic cyanobacteria with SYTOXGreen after lysis by freeze-thaw and lysis by ethanol. This project will focus on two strains of toxic cyanobacteria known as Aphanizomenon - A. flos-aquae and Planktothrix - P. agardhii. The live and dead cells are observed under blue and red fluorescent light to show the effectiveness of each lysis. It is important that this topic is researched because it is significantly affecting our waterways and sometimes drinking water. We often see that you cannot swim in Lake Erie due to algae, more specifically, these …

Genomic And Taxonomic Studies Of An Antarctic Psychrotolerant Quorum Quenching Bacterium, Planococcus Versutus L10.15t, See-Too Wah Seng

Student Works (2020-2029)

Quorum quenching (QQ) has been suggested as an alternative to antibiotic treatments for pathogenic infections as it does not affect the viability of the pathogen and imposes minimum selection pressure promoting drug resistance. During an ecological survey for quorum quenching (QQ) bacteria from soil collected in Lagoon Island (Ryder Bay, Adelaide Island, Antarctica), a bacterial strain was isolated and identified as Planococcus species, L10.15T, based on 16S rRNA gene analysis. The genomic, phylogenetic, chemotaxonomic and phenotypic data obtained showed that L10.15T represents a novel species for which the name Planococcus versutus sp. nov. is proposed. Previously, QQ activity of L10.15T …

Species Richness And Ecological Diversity Of Myxomycetes And Myxomycete-Like Organisms In The Tropical Forests Of Brazil, Isadora Lima Coelho

Graduate Theses and Dissertations

Tropical rain forests cover less than two percent of Earth's surface, yet they sustain the greatest diversity of living organisms on the planet. Tropical rain forests cover nearly 73% of the Brazilian territory and besides harboring some of the most biodiverse ecosystems on the planet, this vast area also houses about 83% of the Brazilian population. Approximately 175 million people live in urban and rural areas with fragments of coverage of these biomes which contributes to the loss of biodiversity that rapidly increases over the years. Furthermore, the majority of the taxonomic and ecological efforts to describe and protect the …

Simulating Bacterial Growth, Competition, And Resistance With Agent-Based Models And Laboratory Experiments, Anne E. Yust, Davida S. Smyth

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Molecular Detection Of Pathogenic Leptospira Throughout The Caribbean, Zamara R. Garcia Truitt

Biology Theses

Leptospirosis is a common widespread zoonotic disease found throughout the Caribbean. The infection is produced by a pathogenic Leptospira species found in tropical and subtropical regions. The severity of the disease ranges from a mild asymptomatic infection to death. Leptospirosis is a neglected tropical disease due to the lack of public awareness and health approaches. Therefore, misdiagnosis is common because the symptoms are similar to that of other tropical endemic diseases. The aim of the study was to determine the presence of pathogenic Leptospira in water samples collected from Puerto Rico and Trinidad. Sixty-four environmental water samples were collected throughout …

Culture-Based Analysis Of ‘Cave Silver’ Biofilms On Rocks In The Former Homestake Mine In South Dakota, Usa, Amanpreet K. Brar, David Bergmann

International Journal of Speleology

Tunnels in a warm, humid area of the 1478 m level of the Sanford Underground Research Facility (SURF), located in a former gold mine in South Dakota, USA, host irregular, thin whitish, iridescent biofilms, which appear superficially similar to ‘cave silver’ biofilms described from limestone and lava tube caves, despite the higher rock temperature (32°C) and differing rock surface (phyllite) present at SURF. In this study, we investigated the diversity of cultivable bacteria constituting the cave silver by using several media: CN agar, CN gellan gum and 0.1X R2A agar. The highest colony count (CFU/g of sample) was observed on …

The Chelation Of Metal Ions By Vicibactin, A Siderophore Produced By Rhizobium Leguminosarum Atcc 14479, Joshua Stinnett

Undergraduate Honors Theses

Vicibactin is a small, high-affinity iron chelator produced by Rhizobium leguminosarum ATCC 14479. Previous work has shown that vicibactin is produced and secreted from the cell to sequester ferric iron from the environment during iron-deplete conditions. This ferric iron is then transported into the cell to be converted into ferrous iron. This study uses UV-Vis spectroscopy as well as ion trap-time of flight mass spectroscopy to determine that vicibactin does form a complex with copper(II) ions, however, at a much lower affinity than for iron(III). Stability tests have shown that the copper(II)-vicibactin complex is stable over time. The results of …

Assessing The Prevalence Of Multidrug Resistant Salmonella Enterica From Stream Sediment And Poultry Litter In The Shenandoah Valley Of Virginia, Noah Greenman

Masters Theses, 2010-2019

Multidrug resistant Salmonella enterica present in stream sediment and poultry litter represent a critical health concern. A small number of S. enterica serotypes are responsible for most lab-confirmed infections in the US each year. To assess the prevalence of these significant strains, we isolated 88 S. enterica from stream sediment and poultry litter. Sequence data for all isolates were generated using an Illumina® sequencing platform, with long-reads for some isolates from the Oxford Nanopore MinION™ used in a hybrid genome assembly approach. Isolates were typed according to their serotype and multi-locus sequence type using SeqSero/SISTR and Enterobase respectively. Antibiotic resistance …

Effects Of 5��-Dihydrotestosterone (Dht) On Mouse Gut Microbiome– A Study Of Sex Differences And Hormonal Effects On Gut Microbiome Composition, Bikesh Shrestha

All Master's Theses

Type 1 Diabetes (T1D) is a polygenic and multifactorial disease, traditionally attributed to genetic susceptibility and diet. Over the past decade, novel studies have placed a higher significance on the role of gut microbiome in T1D pathogenesis. Furthermore, diabetic mouse models have shown higher incidence of T1D in females compared to males, attributed to the differences in gut microbial community structure. Interestingly, female mouse models elicit male-like protection from T1D when transplanted with the male gut microbiome. In a previous study, we observed that female Non-obese diabetic (NOD) mice implanted with slow release 5��-Dihydrotestosterone(DHT) for 90 days showed improved glucose …

Preconditioning Of The Tumor Microenvironment By Means Of Low Dose Chemotherapies For An Effective Immunotherapy Of Breast Cancer, Hussein F. Aqbi

Theses and Dissertations

Breast cancer mortality is mainly due to distant recurrence of the disease arising from dormant tumor cells established by cancer therapies. Patients who initially respond to cancer therapies often succumb to distant recurrence of the disease. It is not clear why people with the same type of breast cancer respond to treatments differently; some escape from dormancy and relapse earlier than others. In addition, some tumor clones respond to immunotherapy while others do not. We investigated how autophagy plays a role in accelerating or delaying recurrence of neu overexpressing mouse mammary carcinoma (MMC) following adriamycin (ADR) treatment, and in affecting …

Phenotypic And Transcriptomic Characterization Of Colonial Phase Variation In The Cholera Pathogen Reveals A Novel Smooth Biofilm-Defective Form, Bliss Nicole Lambert

LSU Doctoral Dissertations

Biofilm formation, through the production of Vibrio polysaccharide (VPS), greatly enhances the environmental fitness and pathogenic success of Vibrio cholerae. As a result of phase variation, V. cholerae can switch from a smooth form to rugose, whose cells produce excess VPS, resulting in highly structured biofilms and greater resistance to stress. To further characterize the reversible process of phase variation, we isolated three colonial lineages. Each lineage began with a smooth parent, N16961, and contained a rugose variant derived from the parent, N16961R, as well as a smooth revertant of the rugose, N16961SD. We found clear phenotypic and transcriptomic …

Harnessing The Anopheles Microbiome To Conditionally Express Anti-Plasmodial Effectors During The Blood Meal, Jackie Shane

Electronic Theses and Dissertations

The control of vector-borne diseases such as malaria has been an extremely important research subject for hundreds of years. Because of the complex lifecycles of the pathogens that cause these diseases, finding a comprehensive treatment or preventative strategy has proven extremely difficult. Malaria alone is responsible for almost half a million deaths annually, most of them children under 5 years old. This disease is caused by parasitic protists in the genus Plasmodium that are transmitted to humans from Anopheles sp. mosquitoes. Most preventative strategies that are in use today revolve around controlling the vectors, including bed nets, insecticides, and larval …

Triatomines: Trypanosomatids, Bacteria, And Viruses Potential Vectors?, Caroline Barreto Viera, Yanna Reis Praça, Kaio Luis Da Silva Bentes, Paula Beatriz Santiago, Sofia Marcelino Martins Silva, Gabriel Dos Santos Silva, Flávia Nader Motta, Izabela Marques Dourado Bastos, Jaime Martins De Santana, Carla Nunes De Araújo

Harold W. Manter Laboratory of Parasitology: Library Materials

Triatominae bugs are the vectors of Chagas disease, a major concern to public health especially in Latin America, where vector-borne Chagas disease has undergone resurgence due mainly to diminished triatomine control in many endemic municipalities. Although the majority of Triatominae species occurs in the Americas, species belonging to the genus Linshcosteus occur in India, and species belonging to the Triatoma rubrofasciata complex have been also identified in Africa, the Middle East, South-East Asia, and in the Western Pacific. Not all of Triatominae species have been found to be infected with Trypanosoma cruzi, but the possibility of establishing vector transmission …

Identification Of Microbiota Associated With The Ectosymbiotic Community Structure Of The Appalachian Brook Crayfish (Cambarus Bartonii), Matthew M. Cooke 6268927, Luke T. Fischer, Taylor Griffin, Sherrie Jeffers

Montview Journal of Research & Scholarship

Microbes play a significant role in ecosystems, effecting the vital functions of other organisms, interspecies relationships, and population sizes. Based upon previous research (Skelton et al., 2016), it has been hypothesized that crayfish symbionts (branchiobdellidans) play a significant role in regulating the amount of microbiota associated with the host. A growing body of knowledge is known regarding both the condition of gill fouling and the annelid worm’s symbiotic relationship with the crayfish (Skelton et al., 2016; Skelton et al., 2016). However, there is little to no evidence available concerning the bacteria’s role in the process (Skelton et al., 2016). Microbial …

Green Tea Polyphenol Epigallocatechin-3-Gallate-Stearate Inhibits The Growth Of Streptococcus Mutans: A Promising New Approach In Caries Prevention, Amy Lynn Melok, Lee Lee, Siti Ayuni Mohamed Yussof, Tinchun Chu

Department of Biology Faculty Scholarship and Creative Works

Streptococcus mutans (S. mutans) is the main etiological bacteria present in the oral cavity that leads to dental caries. All of the S. mutans in the oral cavity form biofilms that adhere to the surfaces of teeth. Dental caries are infections facilitated by the development of biofilm. An esterified derivative of epigallocatechin-3-gallate (EGCG), epigallocatechin-3-gallate-stearate (EGCG-S), was used in this study to assess its ability to inhibit the growth and biofilm formation of S. mutans. The effect of EGCG-S on bacterial growth was evaluated with colony forming units (CFU) and log reduction; biofilm formation was qualitatively determined by Congo red assay, …

Microbiome Of Commercial Broilers Through Evisceration And Immersion Chilling, John A. Handley

Graduate Theses and Dissertations

The United States poultry industry generated 38.6 billion pounds (17,500 metric ton) of meat in 2014 which averaged to 121 pounds (55 kg) per individual of the U.S that same year. Of that meat generated by the poultry industry, an estimated 1 million cases of Salmonellosis will occur. Out of the 1 million cases approximately 40, 000 to 50,000 will be confirmed cases by the CDC. Recently, the USDA has requested changes in the inspection process and are currently allowing processors more freedom to utilize innovation to drive the increase in safer and more desirable foods. The new standards set …

Characterization Of Pinitol Catabolism In Sinorhizobium Meliloti And Its Role In Nodule Occupancy, Angela Irene Kennedy-Mendez

Masters Theses

Sinorhizobium meliloti, which is the nitrogen fixing symbiont of Medicago sativa (alfalfa), was used to test the hypothesis that D-chiro-inositol is an intermediate of pinitol catabolism and that pinitol catabolism plays a role in S. melilot s ability to compete for nodule occupancy. An analytical method, involving gas chromatography and mass spectrometry (GCMS), was developed to detect and separate pinitol and D-chiro-inositol. The S. meliloti wild type, and three isogenic mutant strains (idhA, mocD, and mocE) were grown in minimal medium with pinitol and pinitol plus glycerol. The S. meliloti wild type can utilize pinitol as a sole carbon source, …

Photosynthetic Activity Under Low Light, Danijela Lonco

Williams Honors College, Honors Research Projects

Are bacteria capable of undergoing oxygenic photosynthesis under low-light conditions inside of caves? Inside of an Australian cave, Chlorophyll f was recently discovered. This chlorophyll pigment was found to demonstrate the capability for photosynthesis, suggesting that Chlorophyll f extends the spectrum of usable light needed for oxygenic photosynthesis (Lars, 2015). Due to the findings in this study, a team went to Carlsbad Caverns to see if there were any bacteria capable of undergoing oxygenic photosynthesis under low light.

Ancient Bacteria–Amoeba Relationships And Pathogenic Animal Bacteria, Joan E. Strassmann, Longfei Shu

Biology Faculty Research

Long before bacteria infected humans, they infected amoebas, which remain a potentially important reservoir for human disease. Diverse soil amoebas including Dictyostelium and Acanthamoeba can host intracellular bacteria. Though the internal environment of free-living amoebas is similar in many ways to that of mammalian macrophages, they differ in a number of important ways, including temperature. A new study in PLOS Biology by Taylor-Mulneix et al. demonstrates that Bordetella bronchiseptica has two different gene suites that are activated depending on whether the bacterium finds itself in a hot mammalian or cool amoeba host environment. This study specifically shows that B. …

Preliminary Analyses Of The Diversity Of Soil Microbes On The Campus Of The University Of The Incarnate Word, Viridiana Wheeler

Theses & Dissertations

Soil samples were examined outside Bonilla Science Hall on the campus of the University of the Incarnate Word in San Antonio, Texas, at three time points between the calendar years 2016 and 2017. These time points correspond to Fall, Winter, and Spring. Samples were taken at two topsoil depths, 1 cm and 4 cm, to determine if there is a difference in bacterial load or distribution across the time frame examined.

Soil samples were diluted and plated on nutrient agar plates in order to identify unique colony morphologies. A total of 132 distinct morphological isolates were identified and sequenced. Of …

Microbial Interactions In The Phyllosphere Increase Plant Performance Under Herbivore Biotic Stress, Muhammad Saleem, Nicole Meckes, Zahida H. Pervaiz, Milton B. Traw

Plant and Soil Sciences Faculty Publications

The phyllosphere supports a tremendous diversity of microbes and other organisms. However, little is known about the colonization and survival of pathogenic and beneficial bacteria alone or together in the phyllosphere across the whole plant life-cycle under herbivory, which hinders our ability to understand the role of phyllosphere bacteria on plant performance. We addressed these questions in experiments using four genetically and biogeographically diverse accessions of Arabidopsis thaliana, three ecologically important bacterial strains (Pseudomonas syringae DC3000, Xanthomonas campestris, both pathogens, and Bacillus cereus, plant beneficial) under common garden conditions that included fungus gnats (Bradysia spp.). …

What's In A Name? New Bacterial Species And Changes To Taxonomic Status From 2012 Through 2015, Erik Munson, Karen C. Carroll

Clinical Lab Sciences Faculty Research and Publications

Technological advancements in fields such as molecular genetics and the human microbiome have resulted in an unprecedented recognition of new bacterial genus/species designations by the International Journal of Systematic and Evolutionary Microbiology. Knowledge of designations involving clinically significant bacterial species would benefit clinical microbiologists in the context of emerging pathogens, performance of accurate organism identification, and antimicrobial susceptibility testing. In anticipation of subsequent taxonomic changes being compiled by the Journal of Clinical Microbiology on a biannual basis, this compendium summarizes novel species and taxonomic revisions specific to bacteria derived from human clinical specimens from the calendar years 2012 through …