Microbiology Commons^™

Impacts Of Climate Change On Soil Microorganisms In Northern Hardwood Forests, Carley Jane Kratz

Dissertations, Master's Theses and Master's Reports - Open

As global climate continues to change, it becomes more important to understand possible feedbacks from soils to the climate system. This dissertation focuses on soil microbial community responses to climate change factors in northern hardwood forests. Two soil warming experiments at Harvard Forest in Massachusetts, and a climate change manipulation experiment with both elevated temperature and increased moisture inputs in Michigan were sampled. The hyphal in-growth bag method was to understand how soil fungal biomass and respiration respond to climate change factors. Our results from phospholipid fatty acid (PLFA) analyses suggest that the hyphal in-growth bag method allows relatively pure …

The Prevalence And Effect Of Wolbachia Infection On The Brown Widow Spider (Latrodectus Geometricus), Brittany Dane' Arrington

College of Graduate Studies: Theses & Dissertations

Wolbachia was recently identified in the Brown Widow Spider (Latrodectus geometricus). This symbiont has not previously been found in this genus, therefore the consequences on the host’s population dynamics are unknown. The frequency of endosymbiont infection can provide insight into the population dynamics of the host as this bacteria is known to alter host life history. In my 1^st chapter I determine the prevalence of Wolbachia pipentis infection in in the Brown Widow Spider (Latrodectus geometricus) from five locations in the Southeastern United States. Infection frequency differed significantly among sampling locations, ranging from 20% to …

The Movement Of Escherichia Coli And Enterococci Among Beach Sand, Lyngbya Wollei, And The Water Column: Implications For Human Health, Krystal Ann Bakkila

Wayne State University Theses

Occurrence of the filamentous cyanobacteria Lyngbya wollei has become an increasing concern in the Great Lakes region. Prior to the early 1900's, L. wollei had been occasionally documented in the Great Lakes region, but in the last decade it has been observed with increasing frequency. In the Great Lakes L. wollei has been proliferating, fragmenting, and accumulating ashore, where it decays forming thick detrital mats harboring potentially harmful bacteria such as Escherichia coli and enterococci. While the filamentous green algae species Cladophora glomerata has been well studied in this region, very little research has been done on the cyanobacteria L. …

The Distribution Of Fitness Effects Of Spontaneous Mutations In Vibrio Fischeri, Chelsea K. Jones

Honors Theses and Capstones

Mutations are the ultimate source of the biological diversity on which natural selection acts, but the vast majority of these mutations are harmful. As such, mutations lead to disease states like cancer, extinction of small populations, and can drive pathogen evolution. Unfortunately, because mutations are rare and past studies have been subject to detection biases, very little is known about the distribution of fitness effects from naturally occurring mutations. In this study, we used mutation accumulation and full genome sequencing to capture naturally occurring mutations before they were exposed to the sieve of natural selection in Vibrio fischeri. We …

Effects Of Elevated Salinity And Oxidative Stress On The Physiology Of The Toxigenic Cyanobacterium Microcystis Aeruginosa, Billy Christopher Warhurst

UNF Graduate Theses and Dissertations

Harmful algal blooms (HABs) are found worldwide, particularly in places where warm, well-lit, and stagnant waters are common. HABs can have negative effects on aquatic plants and wildlife due to the reduction in light availability associated with turbidity, decrease in O₂ availability, and the production of secondary metabolites that can harm or even prove lethal. Aquatic ecosystems are regularly being affected by elevated salinity because of recent water management strategies, episodes of drought, and salt water intrusion. This research focused on how salinity levels ranging from 0-10ppt affected physiological attributes such as cellular growth and abundance, cell mortality, toxin …

National Park Service Cave Ecology Inventory And Monitoring Framework, Gretchen M. Baker, Steven J. Taylor, Shawn Thomas, Rick Olson, Kathy Lavoie, Marie Denn, Steven Thomas, Hazel Barton, Kurt Helf, Rene Ohms, Joel Despain, Jim Kennedy, David Larson

National Cave and Karst Management Symposium 2013

A team developed the Cave Ecology Inventory and Monitoring Framework for National Park Service (NPS) units. It contains information for NPS cave managers across the United States to determine how to inventory and monitor cave ecology. Due to the wide geographical scope of NPS caves and their many different types, the document does not prescribe exact protocols. Instead, it provides guidance for what types of inventory and monitoring are possible, a framework for deciding how to prioritize inventory and monitoring activities, and references to specific protocols that are already in place at NPS cave parks.

Keywords: cave ecology, cave microbiology, …

Reversible Inactivation And Desiccation Tolerance Of Silicified Viruses, James R. Laidler, Jessica A. Shugart, Sherry L. Cady, Keith S. Bahjat, Kenneth M. Stedman

Biology Faculty Publications and Presentations

Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To
demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus Sulfolobus spindle-shaped virus Kamchatka, and vaccinia virus are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot
springs. In contrast, bacteriophage PRD1 is not silicified. Moreover, silicification provides viruses with remarkable desiccation
resistance, which could allow extensive aerial dispersal.

Epilithic And Aerophilic Diatoms In The Artificial Environment Of Kungsträdgården Metro Station, Stockholm, Sweden, Lena Norbäck Ivarsson, Magnus Ivarsson, Johannes Lundberg, Therese Sallstedt, Catarina Rydin

International Journal of Speleology

The Kungsträdgården metro station is an artificial and urban subsurface environment illuminated with artificial light. Its ecosystem is almost completely unknown and as a first step to better understand the biology and rock wall habitats the diatom flora was investigated. A total of 12 species were found growing on the rock walls of Kungsträdgården metro station. The results show the diatom flora in Kungsträdgården to be dominated by e.g. Diadesmis contenta, Diadesmis perpusilla, Pinnularia appendiculata, Nitzschia amphibia, Nitzschia sinuata and Diploneis ovalis. One species, Caloneis cf. aerophila, has never been reported from Sweden before. …

Comparative Microbial Community Composition From Secondary Carbonate (Moonmilk) Deposits: Implications For The Cansiliella Servadeii Cave Hygropetric Food Web, Annette Summers Engel, Maurizio G. Paoletti, Mattia Beggio, Luca Dorigo, Alberto Pamio, Tiziano Gomiero, Claudio Furlan, Mauro Brilli, Angelo Leandro Dreon, Roberto Bertoni, Andrea Squartini

International Journal of Speleology

The microbial diversity of moonmilk, a hydrated calcium carbonate speleothem, was evaluated from two Italian caves to provide context for the food web of highly-specialized troglobitic beetles, Cansiliella spp. (Leptodirinae), with distinctive carbon and nitrogen isotope values indicative of a novel food source. The moonmilk and associated percolating waters had low to no extractable chlorophyll, with an average organic C:N ratio of 9, indicating limited allochthonous input and a significant contribution from microbial biomass. The biomass from moonmilk was estimated to be ~10⁴ micro- and meiofaunal individuals per m² and ~10⁷ microbial cells/ml. Betaproteobacteria dominated the …

Litter Conditioning Is Differentially Affected By Leaf Species, Phosphorus Enrichment, And Light Availability, Erin E. Scott

Graduate Theses and Dissertations

Anthropogenic enrichment of nitrogen and phosphorus is one of the most pervasive and detrimental threats to aquatic ecosystems worldwide. In streams that rely on allochthonous basal food resources, such as leaves, nutrient pollution can result in altered food quality and decreased carbon (C) standing stocks. However, the magnitude and mechanisms of this change in quality are poorly understood. Laboratory microcosm studies were conducted to 1) quantify the response of litter C:P to a gradient of phosphorus (P) enrichment (0, 0.05, and 0.5 mg SRP/L) across leaf species with variable levels of degradability (sugar maple and oak), and 2) quantify the …

Uncoupling Between Dinitrogen Fixation And Primary Productivity In The Eastern Mediterranean Sea, Eyal Rahav, Barak Herut, Noga Stambler, Edo Bar-Zeev, Margaret R. Mulholland

OES Faculty Publications

In the nitrogen (N)-impoverished photic zones of many oceanic regions, prokaryotic organisms fixing atmospheric dinitrogen (N₂; diazotrophs) supply an essential source of new nitrogen and fuel primary production. We measured dinitrogen fixation and primary productivity (PP) during the thermally stratified summer period in different water regimes of the oligotrophic eastern Mediterranean Sea, including the Cyprus Eddy and the Rhodes Gyre. Low N₂ fixation rates were measured (0.8-3.2μmol N m-2 d-1) excluding 10-fold higher rates in the Rhodes Gyre and Cyprus Eddy (~20μmol N m^-2 d^-1). The corresponding PP increased from east to west (200-2500μmol …

Plant-Mediated Effects On Microbial Diversity In Mesocosms Of An Oligotrophic Bog, Karl J. Romanowicz Iv

Dissertations, Master's Theses and Master's Reports - Open

Globally, peatlands occupy a small portion of terrestrial land area but contain up to one-third of all soil organic carbon. This carbon pool is vulnerable to increased decomposition under projected climate change scenarios but little is known about how plant functional groups will influence microbial communities responsible for regulating carbon cycling processes. Here we examined initial shifts in microbial community structure within two sampling depths under plant functional group manipulations in mesocosms of an oligotrophic bog. Microbial community composition for bacteria and archaea was characterized using targeted 16S rRNA Illumina gene sequencing. We found statistically distinct spatial patterns between the …

Of Gardens, Microorganisms, And Long Island Sound, Judy Preston

Wrack Lines

How healthy soil can make an environmental difference.

"I happened to turn over a large rounded stone in my garden to find a mesmerizing world of organisms that had, just moments earlier, been going about their business before being exposed to the sunlit world, and me."

The Determinants Of Helminth Infection In Baboons, Rita Monfort

Publications and Research

THE DETERMINANTS OF HELMINTH INFECTION IN BABOONS

Summary Paragraph:

Intestinal parasitic helminths are common in wild primate populations [1, 2] and can impose a significant burden on their host’s fitness. Numerous factors can affect the prevalence and diversity of intestinal parasites in natural populations including environmental factors [3, 4], the host’s behavior and genetics [5, 6]. How these different factors interact in natural populations remains unclear. This is in all probability due to the fact that previous studies have seldom looked at the prevalence and diversity of parasitic helminths in the same species but in different habitats over periods longer …

Two Boundaries Separate Borrelia Burgdorferi Populations In North America, Gabriele Margos, Jean I. Tsao, Santiago Castillo-Ramirez, Yvette A. Girard, Anne G. Hoen

Dartmouth Scholarship

Understanding the spread of infectious diseases is crucial for implementing effective control measures. For this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. Here, we investigate on a continental scale the population structure of Borrelia burgdorferi, the causative agent of Lyme borreliosis (LB), a tick-borne disease, in North America. We test the hypothesis that the observed d population structure is congruent with recent population expansions and that these were preceded by bottlenecks mostly likely caused by the near extirpation in the 1900s …

Composition Of The Adult Digestive Tract Bacterial Microbiome Based On Seven Mouth Surfaces, Tonsils, Throat And Stool Samples, Nicola Segata, Susan Kinder Haake, Peter Mannon, Katherine P. Lemon, Levi Waldron, Dirk Gevers, Curtis Huttenhower, Jacques Izard

Department of Food Science and Technology: Faculty Publications

Background: To understand the relationship between our bacterial microbiome and health, it is essential to define the microbiome in the absence of disease. The digestive tract includes diverse habitats and hosts the human body’s greatest bacterial density. We describe the bacterial community composition of ten digestive tract sites from more than 200 normal adults enrolled in the Human Microbiome Project, and metagenomically determined metabolic potentials of four representative sites.

Results: The microbiota of these diverse habitats formed four groups based on similar community compositions: buccal mucosa, keratinized gingiva, hard palate; saliva, tongue, tonsils, throat; sub- and supra-gingival plaques; …

Effects Of The Parasitic Dinoflagellate Hematodinium Sp. On Blue Crab (Callinectes Sapidus) Activity Predation And Habitat Selection, John M. Tiggelaar Ii

Biological Sciences Theses & Dissertations

The blue crab Callinectes sapidus occurs along the Atlantic and Gulf coasts of the United States, and in high salinity regions, they are subject to lethal infection by the parasitic dinoflagellate Hematodinium. In Virginia's seaside estuaries, the prevalence of Hematodinium infection of C. sapidus can sometimes exceed 50%, threatening the commercial fishery for this species. Indeed, other commercially important crustacean fisheries have approached collapse due to Hematodinium infections. Most studies of this host-parasite interaction have focused on epidemiology, host-pathogen dynamics, and pathogen transmission, and little is known about the impact of the parasite on host behavior and population dynamics. …

Links From Mantle To Microbe At The Lau Integrated Study Site: Insights From A Back-Arc Spreading Center, Margaret K. Tivey, Erin Becker, Roxanne Beinart, Charles R. Fisher, Peter Girguis, Charles H. Langmuir, Peter J. Michael, Anna-Louise Reysenbach

Biology Faculty Publications and Presentations

The Lau Integrated Study Site (ISS) has provided unique opportunities for study of ridge processes because of its back-arc setting in the southwestern Pacific. Its location allows study of a biogeographical province distinct from those of eastern Pacific and mid-Atlantic ridges, and crustal compositions along the ridge lie outside the range of mid-ocean ridge crustal compositions. The Lau ISS is located above a subduction zone, at an oblique angle. The underlying mantle receives water and other elements derived from the downgoing lithospheric slab, with an increase in slab influence from north to south. Water lowers the mantle melting temperature and …

Toward The History Of Study Of Symbiogenesis: On The English Translation Of B. M. Kozo-Polyansky’S A New Principle Of Biology (1924), Victor Fet

Biological Sciences Faculty Research

We reproduce the text by Victor Fet, which was read on 6 October 2011 at the Moscow Society of Naturalists during the presentation of new book translation (B.M. Kozo- Polyansky. Symbiogenesis: A New Principle of Evolution / transl. by Victor Fet; ed. by Victor Fet & Lynn Margulis. Cambridge, Mass.: Harvard University Press, 2010. 138 p.) This half- forgotten book by Boris M. Kozo-Polyansky was known only by name to Western biologists. Victor Fet gives a brief history of this new translation, enthusiastically initiated and supported by Lynn Margulis (1938–2011), a famous naturalist who was always eager to gave credit …

Intra And Interhost Dynamics Shaping Arbovirus Adaptation And Evolution, Alexander T. Ciota

Legacy Theses & Dissertations (2009 - 2024)

Arthropod-borne viruses (arboviruses), which are predominately mosquito-borne and almost exclusively RNA viruses, are maintained in nature in complex transmission cycles involving blood sucking invertebrates and vertebrate hosts. Although over 120 arboviruses are human pathogens responsible for causing a significant and expanding global health burden, a detailed understanding of the complex interactions between these pathogens and their hosts, particularly invertebrate hosts, is lacking. Defining these interactions is necessary if we are to understand the selective pressures and, therefore, evolutionary, adaptive, and epidemiological potential of arboviruses. This requires experimental infection and evolution studies, particularly in vivo, with natural hosts. The results presented …

Control And Passive Treatment Of Runoff From Horse Muck Storage Structures Using Rain Gardens, Hillary K. Otte

Theses and Dissertations--Forestry and Natural Resources

Runoff from livestock operations may contain a variety of pathogens and high levels of nutrients and other harmful contaminants, and is of particular concern in central Kentucky as watersheds are threatened by waste generated from a high concentration of equine activity. Rain gardens are a type of stormwater management tool used to capture and passively treat runoff. This project aimed to incorporate rain gardens into the horse muck storage structures at a thoroughbred facility in the Canr Run watershed in Lexington, Kentucky. Water quality data from soil water within two rain garden muck pads and two control pads, and grab …

Bacterial Community Structure Of Contrasting Soils Underlying Bornean Rain Forests: Inferences From Microarray And Next-Generation Sequencing Methods, Sabrina E. Russo, Ryan Legge, Karrie A. Weber, Eoin L. Brodie, Katherine C. Goldfarb, Andrew K. Benson, Sylvester Tan

School of Biological Sciences: Faculty Publications

Soil microbial diversity is vast, and we lack even basic understanding of how this diversity is distributed ecologically. Using pyrosequencing and microarray methods, we quantified the structure of bacterial communities in two contrasting soils underlying Bornean rain forest (clay and sandy loam) that differ markedly in soil properties, aboveground tree flora, and leaf litter decomposition rates. We found significant soil-related taxonomic and phylogenetic differences between communities that, due to their proximity, are independent of climate. Bacterial communities showed distinct compositional and taxon-abundance distributions that were significantly correlated with the structure of the overlying tree community. Richness of bacteria was greater …

Novel Lineages Of Prochlorococcus And Synechococcus In The Global Oceans, Sijun Huang, Steven W. Wilhelm, H. Rodger Harvey, Karen Taylor, Nianzhi Jiao, Feng Chen

OES Faculty Publications

Picocyanobacteria represented by Prochlorococcus and Synechococcus have an important role in oceanic carbon fixation and nutrient cycling. In this study, we compared the community composition of picocyanobacteria from diverse marine ecosystems ranging from estuary to open oceans, tropical to polar oceans and surface to deep water, based on the sequences of 16S-23S rRNA internal transcribed spacer (ITS). A total of 1339 ITS sequences recovered from 20 samples unveiled diverse and several previously unknown clades of Prochlorococcus and Synechococcus. Six high-light (HL)-adapted Prochlorococcus clades were identified, among which clade HLVI had not been described previously. Prochlorococcus clades HLIII, HLIV and …

Diversity, Distribution, And Expression Of Diazotroph Nifh Genes In Oxygen-Deficient Waters Of The Arabian Sea, Amal Jayakumar, Mamoon M. D. Al-Rshadat, Bess B. Ward, Margaret R. Mulholland

OES Faculty Publications

The Arabian Sea oxygen minimum zone (OMZ), the largest suboxic region in the world's oceans, is responsible for up to half of the global mesopelagic fixed nitrogen ( N ) loss from the ocean via denitrification and anammox. Dinitrogen (N₂) fixation is usually attributed to cyanobacteria in the surface ocean. Model prediction and physiological inhibition of N₂ fixation by oxygen, however, suggest that N₂ fixation should be enhanced near the oxygen-deficient zone (ODZ) of the Arabian Sea. N₂ fixation and cyanobacterial nifH genes (the gene encoding dinitrogenase reductase) have been reported in surface waters overlying …

Grazing On Synechococcus Spp. By The Red-Tide Dinoflagellate Karenia Brevis: Implications For Bloom Dynamics In The Gulf Of Mexico, Leo A. Procise

OES Theses and Dissertations

Karenia brevis, the toxic dinoflagellate responsible for massive red tides in the Gulf of Mexico (GOM), causes fish kills, shellfish poisoning, and acute respiratory irritation in humans. Bloom initiation and maintenance have been linked to the physical environment as well as various nutrient input mechanisms. To date, efforts to quantify nitrogen (N) sources fueling K. brevis blooms in the GOM have not included mixotrophic grazing although many dinoflagellates, including K. brevis, are known to be capable of mixotrophy. This dissertation reports field and laboratory results demonstrating that natural bloom populations and K. brevisisolates from the West Florida …

Microbial Impacts On Endocrine Disrupting Contaminants: Las Vegas Wash And Lake Mead, Nevada, Susanna May Blunt

UNLV Theses, Dissertations, Professional Papers, and Capstones

International concern over endocrine disrupting chemicals (EDCs) has become heightened in recent years as more studies reveal their persistence in the environment and their detrimental effects on wildlife. However, little is known about the role of microorganisms in the fate and transport of these compounds in surface waters. Las Vegas Wash, a stream flowing into Lake Mead and fed primarily by treated wastewater effluent, provided a unique experimental system in which to study the role microorganisms play in the dispersal of these compounds in aquatic systems. Samples were collected from the Las Vegas Wash downstream of the Las Vegas Valley's …

Gravesoil Microbial Community Structure During Carcass Decomposition, Amy E. Maile

Department of Entomology: Dissertations, Theses, and Student Research

Dead bodies placed on soil represent unique challenges for investigators. Although processes in soils can be used to estimate postmortem interval, we know very little about how carcasses and insects affect gravesoil microbial communities.

To address this, the current project was composed of two experiments. Experiment one was conducted to investigate the effect of surface type on carcass decomposition and evaluate soil ecology methods. Experiment two was conducted to investigate the presence of an insect population (Lucilia sericata Meigen) on gravesoil microbial communities. Both experiments were conducted in a laboratory setting using freshly killed mouse carcasses. Mouse carcasses were …

Molecular Diversity Of Fungal Phylotypes Co-Amplified Alongside Nematodes From Coastal And Deep-Sea Marine Environments, Punyasloke Bhadury, Holly Bik, John D. Lambshead, Melanie C. Austen, Gary R. Smerdon, Alex D. Rogers

Hubbard Center for Genome Studies (HCGS)

Nematodes and fungi are both ubiquitous in marine environments, yet few studies have investigated relationships between these two groups. Microbial species share many well-documented interactions with both free-living and parasitic nematode species, and limited data from previous studies have suggested ecological associations between fungi and nematodes in benthic marine habitats. This study aimed to further document the taxonomy and distribution of fungal taxa often co-amplified from nematode specimens. A total of 15 fungal 18S rRNA phylotypes were isolated from nematode specimens representing both deep-sea and shallow water habitats; all fungal isolates displayed high pairwise sequence identities with published data in …

Group Size And Nest Spacing Affect Buggy Creek Virus (Togaviridae: Alphavirus) Infection In Nestling House Sparrows, Valerie A. Brown, Charles R. Brown

Papers in Ornithology

The transmission of parasites and pathogens among vertebrates often depends on host population size, host species diversity, and the extent of crowding among potential hosts, but little is known about how these variables apply to most vector-borne pathogens such as the arboviruses (arthropod-borne viruses). Buggy Creek virus (BCRV; Togaviridae: Alphavirus) is an RNA arbovirus transmitted by the swallow bug (Oeciacus vicarius) to the cliff swallow (Petrochelidon pyrrhonota) and the introduced house sparrow (Passer domesticus) that has recently invaded swallow nesting colonies. The virus has little impact on cliff swallows, but house sparrows are seriously …

Human Pathogen Shown To Cause Disease In The Threatened Elkhorn Coral Acropora Palmata, Kathryn Patterson Sutherland, Sameera Shaban, Jessica L. Joyner, James W. Porter, Erin K. Lipp

Faculty Publications

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments …