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Environmental Microbiology and Microbial Ecology Commons™

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2020

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Articles 61 - 77 of 77

Full-Text Articles in Environmental Microbiology and Microbial Ecology

Survival Of Enterococcus FaeciumIn Turkey Litter Under Different Temperature And Moisture Combinations, Steven G. Mcbride, Benjamin Holland, Pradeep Vasudevan, Joanna B. Mott Jan 2020

Survival Of Enterococcus FaeciumIn Turkey Litter Under Different Temperature And Moisture Combinations, Steven G. Mcbride, Benjamin Holland, Pradeep Vasudevan, Joanna B. Mott

Virginia Journal of Science

Untreated poultry litter introduces a substantial load of fecal pathogens to the environment, impacting agriculture, public health and ecosystem function. There is substantial evidence that temperature and moisture are the primary drivers of fecal bacteria survival across ecosystems. However, both temperature and moisture effects have been shown to be modulated by the matrix in which the fecal bacteria are living. This context dependence highlights the importance of understanding fecal bacteria survival in a variety of matrices in order to implement effective waste management plans. In this study, we determined the survival patterns of Enterococcus faecium in post-use turkey litter under …

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Biocide Resistance As A Result Of Exposure To Biocides Used In Hydraulic Fracturing, Lindsey Schenten Jan 2020

Biocide Resistance As A Result Of Exposure To Biocides Used In Hydraulic Fracturing, Lindsey Schenten

Dissertations, Master's Theses and Master's Reports

Microbial resistance to antimicrobials is an important topic to investigate not only for our health but for the environment. There is a growing concern about expanding microbial resistance to both antibiotics and other antimicrobials such as biocides. We wanted to know how bacteria previously exposed to hydraulic fracturing fluids, including biocides, would react to biocide exposure and what the mechanism of resistance looked like. In order to test this hypothesis bacterial isolates were obtained from water and sediment from a stream that had been previously exposed to a spill of hydraulic fracturing water. Thirty bacterial isolates were obtained from these …

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Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil Jan 2020

Developing Microbial Based Process To Produce High Value Natural Antimicrobial (Glyceollin) In Soybeans And Pullulan From Sucrose, Andrea Zavadil

Electronic Theses and Dissertations

Glyceollin is a secondary metabolite produced under stress conditions by soybean to act as a plant defender to pathogen attack. The antimicrobial nature of glyceollin makes it a promising natural alternative to antibiotics if incorporated into livestock feed. However, production of glyceollin is highly variable, dependent on soybean variety, and fungal elicitor used as inoculum. Our study compares two fungal spore elicitors, Trichoderma reesei and Aspergillus sojae on soybeans of diverse maturity level, and fungal susceptibility to determine highest glyceollin titer. Spore inoculation with T. reesei elicited highest glyceollin titers of 2.42±0.20 mg/g at 120 h, while A. sojae elicited …

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The Host Gatekeeper: Using The Flagellar Pathway To Understand Symbiont Host Adaptation, Adam R. Pollio Jan 2020

The Host Gatekeeper: Using The Flagellar Pathway To Understand Symbiont Host Adaptation, Adam R. Pollio

Graduate Theses, Dissertations, and Problem Reports

The acquisition of microbial partners is a strategy used by a diverse group of arthropods to overcome ecological barriers that might normally make certain niches uninhabitable. The unique phylogenetic opportunities attainable from the natural experiment of the Sodalis-allied clade allow for better understanding of how molecular structures evolve through time. Here, we focus on the evolution of the flagellar synthesis pathway, due to its complexity and ability to diverge in response to ecological pressures. We used this molecular pathway and natural experiment to show that normal evolutionary outcomes associated with symbiosis (i.e., genome reduction) do not explain the predicted conservation …

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Genetic And Biochemical Characterization Of Ergot Alkaloid Synthesizing Fungi And Their Symbionts, Matthew Duane Maust Jan 2020

Genetic And Biochemical Characterization Of Ergot Alkaloid Synthesizing Fungi And Their Symbionts, Matthew Duane Maust

Graduate Theses, Dissertations, and Problem Reports

Ergot alkaloids are fungal tryptophan derived toxins which affect mammalian circulation and neurotransmission. These compounds are biosynthesized by a conserved genetic pathway, known as the ergot alkaloid synthesis (EAS) pathway by fungi belonging to the ascomycete families Trichocomaceae and Clavicipitaceae. Several Ipomoea species and related plants in the morning glory family harbor vertically transmitted symbiotic fungi in the genus Periglandula, also members of Clavicipitaceae, that produce ergot alkaloids. Metabolomic analysis of seeds identified a previously uncharacterized glycoside form of the pharmaceutically important ergot alkaloid, ergonovine. Several species belonging to the fungal genus Metarhizium have recently been shown to have the …

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Massard Prairie Restoration And Soil Microbiome Succession, Jeffrey M. Shaver, Emily S. Bellis, Chizuko Iwaki, Jake Qualls, Jay Randolph, Jeremiah Smith Jan 2020

Massard Prairie Restoration And Soil Microbiome Succession, Jeffrey M. Shaver, Emily S. Bellis, Chizuko Iwaki, Jake Qualls, Jay Randolph, Jeremiah Smith

Journal of the Arkansas Academy of Science

We have initially sequenced soil microbial DNA from 4 restored and 4 virgin tallgrass prairie soil samples from Ben Geren Park and Massard Prairie (Fort Smith, AR), respectively. As expected, the soil microbiomes are distinct, with several lineages of nitrogen-fixing bacteria more common in virgin tall grass prairie. However, we predict that as restoration of tallgrass prairie in Ben Geren Park progresses, the soil microbiome of restored prairie will more closely mirror those of the virgin prairie.

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Microbial Responses To Unconventional Oil And Gas Development May Alter Ecosystem Function In Headwater Streams, Rachel Michaels Jan 2020

Microbial Responses To Unconventional Oil And Gas Development May Alter Ecosystem Function In Headwater Streams, Rachel Michaels

Graduate Theses, Dissertations, and Problem Reports

The demand for natural gas, and the need for efficient extraction, has led to the development of unconventional oil and natural gas (UOG) techniques. Due to the novelty of UOG, the potential impacts to freshwater ecosystems are not fully understood. We used a dual pronged approach to study the effects of UOG development on microbial biodiversity and function via a laboratory microcosm experiment and a survey study of streams with and without UOG development within their watersheds. The laboratory microcosm study simulated stream contamination with produced water, a byproduct of UOG operation, using sediment collected from one high water-quality stream …

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Extracting Secondary Metabolites From Bacterial Endophytes To Suppress Or Promote Sweet Sorghum And Weeds, Mohammad R. Alsabri Jan 2020

Extracting Secondary Metabolites From Bacterial Endophytes To Suppress Or Promote Sweet Sorghum And Weeds, Mohammad R. Alsabri

Theses and Dissertations--Plant and Soil Sciences

Endophytic bacteria are ubiquitous in agricultural settings and have the potential to drastically affect plant growth both positively and negatively. These complex relationships play a key role in plant nutrition and are therefore of great interest to the agricultural community and beyond. With my dissertation work, I have had the opportunity to examine the relationship between endophytic bacteria and plants in various ways. The first part of my dissertation investigated how the microbial diversity found in soil affects the below- and above-ground traits of Sorghum bicolor. In the second section, I focused on a particular strain of bacteria that …

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The Effects Of Staining Cyanobacteria With Sytoxgreen After Lysis By Freeze-Thaw And Lysis By Ethanol, Samantha Galambos Jan 2020

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 …

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Marked Changes In Diversity And Relative Activity Of Picoeukaryotes With Depth In The World Ocean, Caterina R. Giner, Massimo C. Pernice, Vanessa Balagué, Carlos M. Duarte, Josep M. Gasol, Ramiro Logares, Ramon Massana Jan 2020

Marked Changes In Diversity And Relative Activity Of Picoeukaryotes With Depth In The World Ocean, Caterina R. Giner, Massimo C. Pernice, Vanessa Balagué, Carlos M. Duarte, Josep M. Gasol, Ramiro Logares, Ramon Massana

Research outputs 2014 to 2021

Microbial eukaryotes are key components of the ocean plankton. Yet, our understanding of their community composition and activity in different water layers of the ocean is limited, particularly for picoeukaryotes (0.2–3 µm cell size). Here, we examined the picoeukaryotic communities inhabiting different vertical zones of the tropical and subtropical global ocean: surface, deep chlorophyll maximum, mesopelagic (including the deep scattering layer and oxygen minimum zones), and bathypelagic. Communities were analysed by high-tthroughput sequencing of the 18S rRNA gene (V4 region) as represented by DNA (community structure) and RNA (metabolism), followed by delineation of Operational Taxonomic Units (OTUs) at 99% similarity. …

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Investigating Links Between Soil Microbial Structure And Function In Three Major Plant Communities Across Temporal Scales Of Arctic Alaska, Kaj Lynoe Jan 2020

Investigating Links Between Soil Microbial Structure And Function In Three Major Plant Communities Across Temporal Scales Of Arctic Alaska, Kaj Lynoe

Electronic Theses and Dissertations

Arctic microbial systems continue to get attention today as our understanding regarding their structure and function in a changing system is paramount to C feedbacks with warming and changes in precipitation. Plant communities and microbial community processes across the Arctic landscape are central to understanding tundra ecosystem processes because environmental conditions and plant community structure drive microbial cycling of soil organic matter. Here, we want to understand how soil microbial respiration, mineralization, biomass, and community composition are linked to three Alaskan tundra plant communities, namely Shrub, Tussock, and Sedge tundra and the seasonal variability in this system. A total of …

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Microbial Degradation Of Urea Oligomers: Potential Slow Release Nitrogen Fertilizers, Maddy Bygd Jan 2020

Microbial Degradation Of Urea Oligomers: Potential Slow Release Nitrogen Fertilizers, Maddy Bygd

Departmental Honors Projects

Urea is the most commonly used nitrogen compound in fertilizers across the world. It provides the most nitrogen at the lowest cost. However, with the size and solubility of this compound, it is easily washed out of the soil. This results in the need to continuously add fertilizer to fields, creating adverse effects on the environment due to nitrogen runoff and leading to increased expenses for farmers. Triuret, a urea oligomer, is a compound with promising potential for use as a nitrogen source, providing a slower release of nitrogen into the soil. It is hypothesized that this compound can be …

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Determination Of Iron-Reducing Bacterial Activities In Lake Sediments., Alexandra Kahn Jan 2020

Determination Of Iron-Reducing Bacterial Activities In Lake Sediments., Alexandra Kahn

Williams Honors College, Honors Research Projects

Algal blooms are growing rampantly in lacustrine systems due to an increase of phosphorus, a nutrient for algae. Phosphorus is being released into the environment causing overpopulation and eutrophication which damages the ecosystem. The availability of phosphorus is affected by the solubility of iron which is regulated through iron reducing and iron oxidizing bacteria. Phosphorus adheres to insoluble Fe(III), which prohibits algae from utilizing it, while phosphorus does not attach to soluble Fe(II) and therefore it remains available to algae. The purpose of this study was to determine how bacteria influence iron solubility and what are the ideal environmental conditions …

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Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis Jan 2020

Comparison Of Fe(Iii) Reduction Rates By Iron-Reducing Bacteria Within Sub Muros Samples From Quadrilátero Ferrífero Iron-Ore Caves, Brazil, Summer Ellis

Williams Honors College, Honors Research Projects

Previous research investigating the speleogenesis of iron-ore caves (IOC) in the Quadrilátero Ferrífero, or “Iron Quadrangle,” of Brazil suggests that microbial iron reduction and subsequent dissolution of the surrounding Fe(III) rich rocks is responsible for cave formation. A soft intra-wall substance (sub muros) containing iron-reducing bacteria (FeRB) was discovered underneath the durable crusts of cave walls. The goal of the study was to determine if reduction rates were comparable between sub muros samples, while additionally observing how different electron donors affect microbial iron reduction. To do this, I compared Fe(III) reduction rates between sub muros samples collected from …

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Diversity Analysis Of Soil Fungus Communities In Disturbed, Nursery, And Mature Forest Conditions, Dana Whitmore Jan 2020

Diversity Analysis Of Soil Fungus Communities In Disturbed, Nursery, And Mature Forest Conditions, Dana Whitmore

All Master's Theses

Populations of soil fungi were examined in Derby Canyon Natives, Coeur d’Alene Forest Service nursery, Swamp Lake, and the Keechelus Lake wildlife overcrossing soils. All sampling sites were connected by their relation to the revegetation and native soil plug inoculation of the wildlife overpass. This study was an effort to describe soil fungi communities present on the overpass before plant introduction, those that plants would be bringing in their pots, and the fungi that could be introduced via soil plug transplantation. DNA was extracted from soil samples, then sequenced using next-generation sequencing methods, allowing for the analysis of species richness …

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Composition And Bioavailability Of Effluent Dissolved Organic Nitrogen, Quinn Nicole Roberts Jan 2020

Composition And Bioavailability Of Effluent Dissolved Organic Nitrogen, Quinn Nicole Roberts

Dissertations, Theses, and Masters Projects

Cultural eutrophication, the overproduction of phytoplankton biomass in response to increased nutrient inputs directly associated with human activities, is a major threat to the health of Chesapeake Bay. Strict regulations, which require a reduction in nutrient loading from all sources, have been a key component to restoration efforts. Water reclamation facilities (WRFs), which discharge effluent containing nitrogen (N) and other nutrients into receiving waters, have implemented upgrades in an effort to comply with regulations. These improvements have decreased the concentration of highly labile dissolved inorganic N (DIN), leaving behind significant concentrations of dissolved organic N (DON) whose bioavailability, and therefore …

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Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee Jan 2020

Isothermal Environmental Heat Energy Utilization By Transmembrane Electrostatically Localized Protons At The Liquid-Membrane Interface, James Weifu Lee

Chemistry & Biochemistry Faculty Publications

This study employing the latest theory on transmembrane electrostatic proton localization has now, for the first time, consistently elucidated a decades-longstanding bioenergetic conundrum in alkalophilic bacteria and more importantly discovered an entirely new feature: isothermal environmental heat utilization by electrostatically localized protons at the liquid-membrane interface. It was surprisingly revealed that the protonic motive force (equivalent to Gibbs free energy) from the isothermal environmental heat energy utilization through the electrostatically localized protons is not constrained by the overall energetics of the redox-driven proton pump system because of the following: (a) the transmembrane electrostatically localized protons are not free to move …

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