Marine Biology Commons^™

Characterization Of Vibrio Vulnificus Strains Using Phenotypic And Genotypic Assays, James Conrad

Masters Theses, 2010-2019

In this study 143 V. vulnificus isolates of clinical and environmental origin, were examined for growth on differential media, identified to species and tested for antibiotic resistance. A multiplex PCR was created and optimized, and phylogenetic analysis was conducted. The first objective was to compare phenotypic methods to identify V. vulnificus. Colony colors of confirmed V. vulnificus isolates on selective media (Vibrio vulnificus agar, thiosulfate citrate bilesalts sucrose agar, CHROMAgar Vibrio (CAV), and colistin polymyxin B cellobiose agar), mostly matched those characteristic of V. vulnificus. To test the ability of these media to select for V. vulnificus, new presumptive V. …

A Functional Approach To Resolving The Biogeocomplexity Of Two Extreme Environments, Haydn Rubelmann Iii

USF Tampa Graduate Theses and Dissertations

The biodiversity of two distinct marine environments was observed to describe the biogeocomplexity of these extreme ecological systems. A shallow-water hydrothermal vent in Papua New Guinea served as a study of a thermophilic ecosystem influenced by arsenic rich vent fluids while a 60 m deep offshore primarily anoxic karst sink served as a study of an anaerobic sulfur-influenced habitat. Both environments support unique biological communities that are influenced by the physical and chemical pressures imposed on them by the harsh conditions of these systems. In Tutum Bay, Ambitle Isle, Papua New Guinea, a transect was created from a shallow hydrothermal …

Two Distinct Microbial Communities Revealed In The Sponge Cinachyrella, Marie L. Cuvelier, Emily Blake, Rebecca Mulheron, Peter J. Mccarthy, Patricia Blackwelder, Rebecca Vega-Thurber, Jose V. Lopez

Marine & Environmental Sciences Faculty Articles

Marine sponges are vital components of benthic and coral reef ecosystems, providing shelter and nutrition for many organisms. In addition, sponges act as an essential carbon and nutrient link between the pelagic and benthic environment by filtering large quantities of seawater. Many sponge species harbor a diverse microbial community (including Archaea, Bacteria and Eukaryotes), which can constitute up to 50% of the sponge biomass. Sponges of the genus Cinachyrella are common in Caribbean and Floridian reefs and their archaeal and bacterial microbiomes were explored here using 16S rRNA gene tag pyrosequencing. Cinachyrella specimens and seawater samples were collected from the …

Predation Thresholds In Marine Microbial Communities Applied To Environments With Low Prey Abundances, Bonnie Bailey

OES Theses and Dissertations

Prokaryotes (Bacteria and Archaea) comprise the largest component of biomass in the world's oceans. Their abundances are controlled by resource availability, viral infections and protist grazing. Many pico- and nano-eukaryotic predators grow almost as quickly as their prey, and greatly increase in numbers as soon as their prey do, leading in tum to depletion in prokaryotes. It is still unclear however, as to what extent microbial predators are able to feed in low prey environments, most prominently in the largest biome on Earth, the deep sea (below l 000 m depth). It has been hypothesized that in low prey environments, …

The Effects Of Ocean Acidification And Eutrophication On The Growth, Lipid Composition And Toxicity Of The Marine Raphidophyte Heterosigma Akashiwo., Julia Rose Matheson

Electronic Thesis and Dissertation Repository

Anthropogenic forcing, such as ocean acidification caused by rising carbon dioxide emissions, and eutrophication due to increased nutrient loadings in run-off, are causing major changes to the biogeochemistry of the oceans. As a consequence, coastal phytoplankton are susceptible to altered biogeochemical environments. This study examined the effect of a lower pH and increased levels of nutrients on the common coastal harmful alga, Heterosigma akashiwo. Growth rates, maximal cell yields, neutral lipid accumulation and toxicity of cells grown under various pH and nutrients regimes were measured. H. akashiwo growth was near maximal when grown at lower pH levels. There was …

Quantitative Depth Profile Of Prochlorococcus In The Pacific Ocean, Benjamin Carter Calfee

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Prochlorococcus is a genus of extremely abundant marine cyanobacterium. This microbe is responsible for the majority of the primary production within marine environments and is thought to be the single most abundant photosynthetic organism. In addition to accounting for such a large portion of the world’s photosynthetic activity, Prochlorococcus functions with a genome much smaller than most other primary producers. Thus due to its general abundance and overall importance in oceanic ecosystems, an experiment was prompted to derive the spatial and numerical separation of the members of this genus across the Pacific Ocean through the use of quantitative polymerase chain …

Environmental Influences On Bacterio-Phytoplanktonic Coupling And Bacterial Growth Efficiency In A Sub-Tropical Estuary, Rachel Kotkowski

FIU Electronic Theses and Dissertations

Bacterio-phytoplanktonic coupling and bacterial growth efficiency (BGE) measurements were used to analyze microbial trophic dynamics and the influence of environmental factors in Florida Bay, Florida. Phytoplankton gross primary productivity (GPP) was measured using 24-hour in situ oxygen incubations; bacterial productivity (BP) was measured using ³H- thymidine incorporation. Weak bacterio-phytoplanktonic coupling was observed over the sampling period. BP was more influenced by local total nitrogen concentrations while GPP was more evenly distributed. BGE rates were low but consistent with marine and estuarine ecosystems worldwide. Results suggest that bacterioplankton growth in Florida Bay is relatively uncoupled from phytoplankton production, which may …

The Roles Of Microcystin And Sulfide In Physiology And Tactic Responses Of Pathogenic And Non-Pathogenic Mat-Forming Cyanobacteria, Abigael C. Brownell

FIU Electronic Theses and Dissertations

Planktothricoides raciborskii and Roseofilum reptotaenium are physiologically similar, yet ecologically distinct organisms found in a hot spring outflow and coral black band disease (BBD), respectively. The aim of this study was to elucidate the relationship between R. reptotaenium and sulfide in BBD, to compare microcystin (MC) production in response to environmental factors, and to determine chemotactic responses to MC and sulfide by the two organisms. Results showed that the pathogenicity of R. reptotaenium in BBD is dependent on sulfate-reducing bacteria as secondary pathogens. Roseofilum reptotaenium produced significantly more MC than P. raciborskii, as measured using ELISA. Roseofilum reptotaenium …

Structure And Function Of Zooplankton-Associated Bacterial Communities In A Temperate Estuary Change More With Time Than With Zooplankton Species, Samatha L. Bickel, Kam W. Tang, Hans-Peter Grossart

VIMS Articles

Zooplankton support distinct bacterial communities in high concentrations relative to the surrounding water, but little is known about how the compositions and functionalities of these bacterial communities change through time in relation to environmental conditions. We conducted a year-long field study of bacterial communities associated with common zooplankton groups as well as free-living bacterial communities in the York River, a tributary of Chesapeake Bay. Bacterial community genetic fingerprints and their carbon substrate usage were examined by denaturing gradient gel electrophoresis (DGGE) of amplified 16S rDNA and by Biolog EcoPlates, respectively. Zooplankton-associated communities were genetically distinct from free-living bacterial communities but …

Comparafac: A Library And Tools For Rapid And Quantitative Comparison Of Dissolved Organic Matter Components Resolved By Parallel Factor Analysis., Thomas B. Parr, Tsutomu Ohno, Kevin Simon

Publications

Parallel Factor Analysis (PARAFAC) is a well-established method for characterizing dissolved organic matter (DOM). While methods for sample processing and PARAFAC analysis are well defined and robust, subsequent classification of DOM fluorescence components and comparisons of components among studies remain highly qualitative. Because these comparisons often guide the interpretation of subsequent data, it is important that quantitatively accurate comparisons be made. We developed a statistical tool, comPARAFAC, using a modified Tucker’s Congruence Coefficient (mTCC), an established method of factor comparison, to provide a quantitative basis for comparing models. To develop and test this tool we used mTCC to compare factors …

Impacts Of Freshwater Flushing On Anammox Community Structure And Activities In The New River Estuary, Usa, Ja Lisa, B Song, Cr Tobias, Ka Duernberger

VIMS Articles

Anaerobic ammonium oxidation (anammox) and denitrification are 2 microbial nitrogen removal processes that may play an important role in controlling the intensity and duration of estuarine and coastal eutrophication. Sediment communities in the New River Estuary, North Carolina were investigated to determine the dynamics of anammox activity and community structure in conjunction with environmental conditions. N-15 tracer incubation experiments with sediment slurries were used to measure anammox and denitrification rates and estimate anammox contribution to total N-2 production. Molecular analyses targeting the hydrazine oxidoreductase (hzo) gene were conducted to examine the structure of anammox communities and quantify the abundance of …

Emergence Of Algal Blooms: The Effects Of Short-Term Variability In Water Quality On Phytoplankton Abundance, Diversity, And Community Composition In A Tidal Estuary, Todd A. Egerton, Ryan E. Morse, Harold G. Marshall, Margaret R. Mulholland

OES Faculty Publications

Algal blooms are dynamic phenomena, often attributed to environmental parameters that vary on short timescales (e.g., hours to days). Phytoplankton monitoring programs are largely designed to examine long-term trends and interannual variability. In order to better understand and evaluate the relationships between water quality variables and the genesis of algal blooms, daily samples were collected over a 34 day period in the eutrophic Lafayette River, a tidal tributary within Chesapeake Bay's estuarine complex, during spring 2006. During this period two distinct algal blooms occurred; the first was a cryptomonad bloom and this was followed by a bloom of the mixotrophic …

Phytoplankton And Nutrient Dynamics In A Tidally Dominated Eutrophic Estuary: Daily Variability And Controls On Bloom Formation, Ryan E. Morse, Margaret R. Mulholland, Todd A. Egerton, Harold G. Marshall

OES Faculty Publications

To better understand nutrient dynamics and factors that promote the initiation of algal blooms, the Lafayette River, a tidal subestuary of Chesapeake Bay that experiences seasonal algal blooms, was sampled daily for a period of 54 d in the fall of 2005. Three phytoplankton blooms (chl a concentrations exceeding twice the average of monthly measurements from 2000 to 2009) occurred during this period: a mixed bloom of Akashiwo sanguinea and Gymnodinium sp., a monospecific Skeletonema costatum bloom, and a monospecific Gymnodinium sp. bloom. Over the sampling period, nutrient concentrations increased following precipitation events and were elevated between bloom periods but …

Microzooplankton Growth Rates Examined Across A Temperature Gradient In The Barents Sea, Gayantonia Franzè, Peter J. Lavrentyev

Peter J. Lavrentyev