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The Spatial, Temporal, And Ecological Constraints Of Plant-Host Associated Microbial Communities, Jonathan Dickey
The Spatial, Temporal, And Ecological Constraints Of Plant-Host Associated Microbial Communities, Jonathan Dickey
Doctoral Dissertations
With the development of next generation sequencing technology, ecologists have recently been able to describe microbial communities across a wide array of niches at an accelerated pace. De-novo-based patterns in richness and relative abundance have been described for bacterial and fungal communities in terrestrial, aquatic, and host-associated microhabitats. A recent synthesis has shown that these communities exhibit similar geographical patterns that have been traditionally described for plant and animals. Yet, there is a lack of hypothesis-based research for host-associated microbial communities. Throughout this dissertation, I will address how spatial scale, sequencing resolution, and manipulative rainfall exclusion govern host-associated microbial communities …
Distribution, Diversity, And Biogeography Of Anaerobic Carbon Monoxide Uptake By Microbial Communities In Soils And Sediments, Amber N. Depoy
Distribution, Diversity, And Biogeography Of Anaerobic Carbon Monoxide Uptake By Microbial Communities In Soils And Sediments, Amber N. Depoy
LSU Master's Theses
Carbon monoxide (CO) is primarily known for being a toxic gas. However, CO is used by microorganisms as an electron or carbon source in a variety of respiratory processes. Different kinds of microorganisms utilize CO aerobically and anaerobically, using two distinct CO dehydrogenases (CODHs). Aerobes oxidize CO using a molybdenum-dependent dehydrogenase (Mo-CODH), while anaerobes utilize a nickel-dependent CO dehydrogenase (Ni-CODH). Studies of the biochemistry and microbiology of aerobic and anaerobic CO oxidation are extensive, but relatively little is known about the ecology of anaerobic CO oxidation. In an effort to test new hypotheses about the ecology of anaerobic CO oxidation, …
Theoretical And Quantitative Methods Connecting Characterizing Micoribal Metabolism Diversity: Implciations From Phylogenetics, Community Diversity, And Organic Geochemistry, Taylor Royalty
Doctoral Dissertations
Biogeochemistry is controlled by microorganisms obtaining nutrients and energy. Thus, microbial metabolisms directly link microbial ecology and geochemistry. The extent that microbial ecology and geochemistry microbial ecology and geochemistry affects the other requires constraint on the spatiotemporal distribution and abundance of microbial metabolisms with respect to geochemistry, or the microbial niches. Elucidating microbial metabolisms was challenging prior to the advent of ‘omics sequencing technologies, as most microbial lineages lack cultured representatives. Although revolutionizing microbial ecology, challenges still exist in fully leveraging information derived from ‘omics technologies. This dissertation attempts to address a small subset of these challenges that include quantifying …
Microbial Community Richness Distinguishes Shark Species Microbiomes In South Florida, Rachael Cassandra Karns
Microbial Community Richness Distinguishes Shark Species Microbiomes In South Florida, Rachael Cassandra Karns
HCNSO Student Theses and Dissertations
The microbiome (microbial community) of individuals is crucial when characterizing and understanding processes that are required for organism function and survival. Microbial organisms, which make up an individual’s microbiome, can be linked to disease or function of the host organism. In humans, individuals differ substantially in their microbiome compositions in various areas of the body. The cause of much of the composition diversity is yet unexplained, however, it is speculated that habitat, diet, and early exposure to microbes could be altering the microbiomes of individuals (Human Microbiome Project Consortium, 2012b, 2012a). To date, only one study has reported on microbiome …
Bacterial Diversity And Function Within An Epigenic Cave System And Implications For Other Limestone Cave Systems, Kathleen Merritt Brannen-Donnelly
Bacterial Diversity And Function Within An Epigenic Cave System And Implications For Other Limestone Cave Systems, Kathleen Merritt Brannen-Donnelly
Doctoral Dissertations
There are approximately 48,000 known cave systems in the United States of America, with caves formed in carbonate karst terrains being the most common. Epigenic systems develop from the downward flow of meteoric water through carbonate bedrock and the solutional enlargement of interconnected subsurface conduits. Despite carbonate karst aquifers being globally extensive and important drinking water sources, microbial diversity and function are poorly understood compared to other Earth environments. After several decades of research, studies have shown that microorganisms in caves affect water quality, rates of carbonate dissolution and precipitation, and ecosystem nutrition through organic matter cycling. However, limited prior …
Diversity And Function Of Sulfur Cycling Microorganisms In Sediments From Subglacial Lake Whillans, Antarctica, Alicia Marie Purcell
Diversity And Function Of Sulfur Cycling Microorganisms In Sediments From Subglacial Lake Whillans, Antarctica, Alicia Marie Purcell
Masters Theses
There is a growing consensus that metabolically and phylogenetically diverse assemblages of microorganisms mediate subglacial nutrient and elemental cycling. Subglacial Lake Whillans (SLW), located under 801 m of glacial ice, was recently penetrated using environmentally clean protocols. SLW is a permanently dark, cold (-0.5 °C [degrees Celsius]), and shallow (~2.2 m) freshwater lake beneath the West Antarctic Ice Sheet. The presence and diversity of key functional genes involved in dissimilatory sulfur oxidation and reduction were examined at various depths in two sediment cores taken from SLW. Our data show a diversity of sulfur transformation genes throughout the top 34 cm …
Diversity And Activity Of Roseobacters And Roseophage, Charles Ryan Budinoff
Diversity And Activity Of Roseobacters And Roseophage, Charles Ryan Budinoff
Doctoral Dissertations
Bacteria of the Roseobacter lineage are dominant bacterioplankton in coastal systems and contribute significantly to secondary production in oceanic environments. Generalities of Roseobacter ecology, diversity, and distributions are known, but the intraspecific differences between species and their dynamics over short temporal periods is not well understood. Bacteriophage that infect Roseobacters (‘roseophage’) have the potential to shunt secondary production into the dissolved carbon pool and through the process of infection alter Roseobacter physiology. Despite their significance, little effort was made prior to the onset of this study to characterize roseophage. Using culture dependent and independent approaches, I describe the diversity and …