Environmental Microbiology and Microbial Ecology Commons^™

The Contribution Of Marine Aggregate-Associated Bacteria To The Accumulation Of Pathogenic Bacteria In Oysters: An Agent-Based Model, Andrew M. Kramer, J. Evan Ward, Fred C. Dobbs, Melissa L. Pierce

OES Faculty Publications

Bivalves process large volumes of water, leading to their accumulation of bacteria, including potential human pathogens (e.g., vibrios). These bacteria are captured at low efficiencies when freely suspended in the water column, but they also attach to marine aggregates, which are captured with near 100% efficiency. For this reason, and because they are often enriched with heterotrophic bacteria, marine aggregates have been hypothesized to function as important transporters of bacteria into bivalves. The relative contribution of aggregates and unattached bacteria to the accumulation of these cells, however, is unknown. We developed an agent-based model to simulate accumulation of vibrio-type bacteria …

Response Of Soil Microbial Communities To Saltwater Intrusion In Tidal Freshwater Wetlands, Chansotheary Dang

Theses and Dissertations

Saltwater intrusion due to global change is expected to have a detrimental effect on the biogeochemistry of tidal freshwater wetlands. Of particular concern is that fact that salinization can alter the role of these ecosystems in the global carbon cycling by causing shifts in microbial metabolism that alter greenhouse gas emissions and increase carbon mineralization rates. However, our understanding of how wetland microbial community dynamics will respond to saltwater intrusion is limited. To address this knowledge gap and increase our understanding of how microbial communities in tidal freshwater wetlands change over time (1, 3, 12, and 49 weeks) under elevated …

Sulfate-Reducing Bacteria Community Analysis: Isco/Isb Coupled Remediation, Christopher K. Bartlett

Theses and Dissertations (Comprehensive)

Improved techniques for remediating groundwater systems are required for the more than 500,000 contaminated sites in North America. Many of these sites are the legacy of historical industrial operations, inappropriate disposal practices and accidental releases. The most widely observed contaminant at many of these sites is petroleum hydrocarbons (PHCs). Recently, remediation efforts that involve the sequential application of treatment technologies have gained widespread interest. One specific sequential technology application or treatment train employs the aggressive nature of a chemical oxidation followed by bioremediation for polishing. When persulfate is used as the chemical oxidant its natural degradation by-product is sulfate, an …

Arbuscular Mycorrhizal Fungi Of Northern White Cedar (Thuja Occidentalis L.): Habitat Effects On Fungal Communities And Inoculum Effects On Plant Growth On Acid Peat Soils, Guswarni Anwar

Dissertations, Master's Theses and Master's Reports

The relationship of arbuscular mycorrhizal (AM) fungi with northern white cedar (NWC) was examined from the perspective of both fundamental questions about habitat specificity in the root fungal community, as well as applied questions regarding AM fungal efficacy in NWC restoration in peat soils. I performed two experiments testing the effects of AM fungi on survival, growth, and nutrition of NWC seedlings; and one molecular study to determine the habitat effects on community composition of NWC root-associated fungi. First, a greenhouse AM inoculation experiment was conducted in factorial combination with fertilization and liming to examine conditional effectiveness of AM fungal …

Super-Killers: Environmental Isolates That Antagonize Pathogenic Vibrio, Abigail Joy

Honors Projects

Vibrio are members of a bacterial group that thrive in diverse aquatic environments including on the surface of aquatic animals, free-living in the water column, and in association with suspended particles. The total Vibrio counts in the coastal ocean ranges from 10³-10⁵ per milliliter of water depending on seasons and water temperature. Although many different species of Vibrio persist in the water column, pathogenic strains, such as Vibrio cholerae and Vibrio parahaemolyticus are absent or rare in marine environments. We hypothesize that the low abundance of these pathogenic species may be due to interspecific competition among environmental …

Fungi On White-Nose Infected Bats (Myotis Spp.) In Eastern Canada Show No Decline In Diversity Associated With Pseudogymnoascus Destructans (Ascomycota: Pseudeurotiaceae), Karen J. Vanderwolf, David Malloch, Donald F. Mcalpine

International Journal of Speleology

The introduction of the fungal pathogen Pseudogymnoascus destructans (Pd) to North America has stimulated research on the poorly known mycology of caves. It is possible that the introduction of Pd reduces the diversity of fungi associated with bats hibernating in caves. To test this hypothesis we examined the fungal assemblages associated with hibernating bats (Myotis spp.) pre- and post- white-nose syndrome (WNS) infection in eastern Canada using culture-dependent methods. We found the mean number of fungal taxa isolated from bats/hibernaculum was not significantly different between pre-infection (29.6 ± 6.1SD) and post-infection with WNS (32.4 ± 4.3). Although …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

The Human Gut Mycobiome: Pitfalls And Potentials — A Mycologist's Perspective, Mallory J. Suhr, Heather E. Hallen-Adams

Department of Food Science and Technology: Faculty Publications

We have entered the Age of the Microbiome, with new studies appearing constantly and whole journals devoted to the human microbiome. While bacteria outnumber other gut microbes by orders of magnitude, eukaryotes are consistently found in the human gut, and are represented primarily by the fungi. Compiling 36 studies spanning from 1917 to 2015, we found at least 267 distinct fungal taxa have been reported from the human gut, and seemingly every new study includes one or more fungi not previously described from this niche. This diversity, while impressive, is illusory. If we examine gut fungi, we will quickly observe …

Intrinsic Challenges In Ancient Microbiome Reconstruction Using 16s Rrna Gene Amplification, Kirsten Ziesemer, Allison Mann, Krithivasan Sankaranarayanan, Hannes Schroeder, Andrew T. Ozga, Bernd W. Brandt, Egija Zaura, Andrea Waters-Rist, Menno Hoogland, Domingo C. Salazar-Garcia, Mark Aldenderfer, Camilla Speller, Jessica Hendy, Darlene A. Weston, Sandy J. Macdonald, Gavin H. Thomas, Matthew J. Collins, Cecil M. Lewis Jr., Corinne Hofman, Christina Warinner

Biology Faculty Articles

To date, characterization of ancient oral (dental calculus) and gut (coprolite) microbiota has been primarily accomplished through a metataxonomic approach involving targeted amplification of one or more variable regions in the 16S rRNA gene. Specifically, the V3 region (E. coli341–534) of this gene has been suggested as an excellent candidate for ancient DNA amplification and microbial community reconstruction. However, in practice this metataxonomic approach often produces highly skewed taxonomic frequency data. In this study, we use non-targeted (shotgun metagenomics) sequencing methods to better understand skewed microbial profiles observed in four ancient dental calculus specimens previously analyzed by amplicon …

Seeps And Springs At A Platteville “Observatory” On The River Bluffs, Bj Bonin, Greg Brick, Julia R. Steenberg

Sinkhole Conference 2015

Residential building construction along the Mississippi River bluffs in the 1970s created a unique enclosed outcrop of the Late Ordovician Platteville Formation at Lilydale, Minnesota. This outcrop was examined in early 2013 after a newly-formed spring flooded an elevator shaft the previous year, drawing attention to the foundation conditions. The Lexington Riverside property is a six story condominium complex constructed within the top of the bluff. A two-level underground parking garage was built into the bluff. Bedrock was mechanically excavated to accommodate the construction of the building, creating an unweathered rock surface. The space between the structure and the excavated …

A Tail Of Two Phages: Genomic And Functional Analysis Of Listeria Monocytogenes Phages Vb_Lmos_188 And Vb_Lmos_293 Reveal The Receptor-Binding Proteins Involved In Host Specificity, Aidan Casey, Kieran Jordan, Horst Neve, Aidan Coffey, Olivia Mcauliffe

Department of Biological Sciences Publications

The physical characteristics of bacteriophages establish them as viable candidates for downstream development of pathogen detection assays and biocontrol measures. To utilize phages for such purposes, a detailed knowledge of their host interaction mechanisms is a prerequisite. There is currently a wealth of knowledge available concerning Gram-negative phage-host interaction, but little by comparison for Gram-positive phages and Listeria phages in particular. In this research, the lytic spectrum of two recently isolated Listeria monocytogenes phages (vB_LmoS_188 and vB_LmoS_293) was determined, and the genomic basis for their observed serotype 4b/4e host-specificity was investigated using comparative genomics. The late tail genes of these …

Bacteriophages Isolated From Lake Michigan Demonstrate Broad Host-Range Across Several Bacterial Phyla, Kema Malki, Alex Kula, Katherine Bruder, Emily Sible, Thomas Hatzopoulos, Stephanie Steidel, Siobhan C. Watkins, Catherine Putonti

Biology: Faculty Publications and Other Works

BACKGROUND:

The study of bacteriophages continues to generate key information about microbial interactions in the environment. Many phenotypic characteristics of bacteriophages cannot be examined by sequencing alone, further highlighting the necessity for isolation and examination of phages from environmental samples. While much of our current knowledge base has been generated by the study of marine phages, freshwater viruses are understudied in comparison. Our group has previously conducted metagenomics-based studies samples collected from Lake Michigan - the data presented in this study relate to four phages that were extracted from the same samples.

FINDINGS:

Four phages were extracted from Lake Michigan …

The Contribution Of Syntrophic Fatty-Acid Degrading Microbial Communities To Anaerobic Digester Function And Stability, Prince Peter Mathai

Dissertations (1934 -)

Anaerobic digestion (AD), the conversion of complex organic matter to methane, occurs through a series of reactions mediated by different guilds of microorganisms. AD process imbalances, such as organic overload or high organic loading rates (OLR), can result in the accumulation of volatile fatty acids (VFA) e.g., propionate, which must be degraded to maintain stable reactor function. VFAs are metabolized by syntrophic fatty-acid degrading bacteria (SFAB) in association with methanogenic archaea (collectively, syntrophic microbial communities, SMC). Despite their indispensable role in AD, little is known about the ecology of SFAB, especially under stressed conditions. To facilitate ecological studies, four quantitative …

Demographics And Transfer Of Escherichia Coli Within Bos Taurus Populations, Joshua Ryan Dillard

Master's Theses

In the United States, symptoms caused by pathogenic strains of Escherichia coli are on the rise. A major source of these pathogenic strains is the E. coli in the digestive tract of cattle. The purpose of this project was to determine if E. coli are transferred between individuals of the same species and if interspecies transmission is possible. Proximity of cattle was also studied as a contributing factor to the transfer of E. coli. To accomplish this goal, E. coli isolates from cattle and cohabitating ground squirrels were compared through a new method of bacterial strain typing called pyroprinting. …

An Exploration Of The Phylogenetic Placement Of Recently Discovered Ultrasmall Archaeal Lineages, Jeffrey M. O'Brien

Honors Scholar Theses

In recent years, several new clades within the domain Achaea have been discovered. This is due in part to microbiological sampling of novel environments, and the increasing ability to detect and sequence uncultivable organisms through metagenomic analysis. These organisms share certain features, such as small cell size and streamlined genomes. Reduction in genome size can present difficulties to phylogenetic reconstruction programs. Since there is less genetic data to work with, these organisms often have missing genes in concatenated multiple sequence alignments. Evolutionary Biologists have not reached a consensus on the placement of these lineages in the archaeal evolutionary tree. There …

Suitability Of Great South Bay, New York To Blooms Of Pfiesteria Piscicida And P. Shumwayae Prior To Superstorm Sandy, October 29, 2012, Pawel Tomasz Zablocki

Theses and Dissertations

Pfiesteria piscicida and P. shumwayae are toxic dinoflagellates implicated in massive fish kills in North Carolina and Maryland during 1990s. A set of physical, chemica l, and biological factors influence population dynamics of these organisms. This study employs i nformation gathered from relevant literature on temperature, salinity, dissolved oxygen, pH, turbulent mixing, and dissolved nutrients, bacteria, algae, microzooplankton, mesozooplankton, bivalve m ollusks, finfish, and other toxic dinoflagellates, which influence Pfiesteria population dynamics. The research focused on whether conditions in the Great South Bay, Long Island, New York were suitable to blooms of Pfiesteria species prior to the passage of superstorm …

You Don’T Have To Go Home But You Carrot Stay Here: Root-Knot Nematode Biological Control In Carrots, Casey R. Martin, Sahar Abdelrazek, Lori A. Hoagland

The Summer Undergraduate Research Fellowship (SURF) Symposium

Root-knot nematodes cause tens of billions of dollars in damages annually in agricultural production. The enormous economic losses brought about by nematodes, combined with the downsides to current methods for handling them, have led to an increased focus in understanding natural plant defense mechanisms and finding alternative methods to lessen the damage done by root-knot nematodes. Endophyte biocontrol agents such as Trichoderma harzianum have shown promise in reducing nematode damage. Recent studies have demonstrated that soil management practices and plant genotype can influence endophyte community structure, but it is unclear whether such differences influence susceptibility to nematode damage. This study …

How Many Particles Are Present In The Air? Bioaerosol Detection Using An Air Particle Counter, Angie Pamela Rivera, Parag Vaishampayan

STAR Program Research Presentations

Relative cleanliness in terms of particle abundance in spacecraft assembly facilities is determined by particle counts carried out in clean rooms during resting conditions. Particle counters assess total particles and particle size distribution, but do not distinguish inert particles from biological particles, which may include bacterial spores that are resistant to standard cleanroom sterilization procedures. Current cleanroom certifications do not fully assess the effects of human presence on spacecraft contamination since humans are known symbionts to enumerate microorganisms and assessments are performed at rest when there is no human presence. In this study, contamination risks and bioburden in spacecraft assembly …

Collecting Diverse Microorganisms From Rover Spacecraft, Jennifer I. Jacobs, Arianna Jefferson, Heidi Aronson, James Tan, Wayne Schubert, Parag Vaishampayan

STAR Program Research Presentations

. The Planetary Protection discipline at NASA’s Jet Propulsion Laboratory develops and implements procedures to prevent both forward and backward contamination between the Earth and solar system bodies. However, there will always be some microorganisms that will be resistant to the strictest of sterilization methods. In order understand the microorganisms found on spacecraft during assembly, and to rapidly identify them, a mass spectrometry approach was developed. As an experimental approach, a custom database was created for a subset of microorganisms in the Planetary Protection Archive. In order to make the database as accurate and efficient as possible, several different procedures …

Isolation Of Possible Biocontrol Endophytic Bacteria From Solanum Tuberosum Effective Against Streptomyces Scabies., Annie Flatley, Luke Ogle, Adam Noel, Erica Fraley, Alaxandra Goodman, Donna Becker

Poster Sessions

Use of biological control offers a cost effective and environmentally safe method for controlling plant diseases. Biocontrol agents that can colonize roots and live endophytically within plant tissue should allow for effective disease control. The goal of this research was to develop protocols to isolate putative Streptomyces species from potato stem and tuber tissue due to their ability to produce inhibitory compounds which could potentially reduce diseases caused by Streptomyces scabies. Endophyte isolation from Solanum tuberosum (potato) plants (stem and tuber tissues) that were grown in a biocontrol field trial were the focus of this study. Several surface …