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Full-Text Articles in Life Sciences

The Performance Of Bacterial Phytosensing Transgenic Tobacco Under Field Conditions, Michael Harrison Fethe Dec 2013

The Performance Of Bacterial Phytosensing Transgenic Tobacco Under Field Conditions, Michael Harrison Fethe

Masters Theses

Currently the platforms for wide-area detection of environmental contamination are limited. Therefore, there is interest in developing new platforms, especially for use in crop plants to detect and report the presence of biotic and abiotic stress agents. A biosensor uses a biological organism or substrate to detect the presence of an elicitor (i.e., heavy metal, TNT, or bacteria). The foundational groundwork to create biosensors in transgenic plants exists. The creation of bacterial phytosensing transgenic tobacco containing an orange fluorescent protein (OFP) reporter driven by synthetic pathogen-inducible promoters provides a fluorescent signal when infected with phytopathogens for earlier detection in the …


Environmental Constraints On Cyanomyophage Abundance In The Subtropical Pacific Ocean, Tiana Maria Pimentel Dec 2013

Environmental Constraints On Cyanomyophage Abundance In The Subtropical Pacific Ocean, Tiana Maria Pimentel

Masters Theses

Viruses are abundant in the world’s oceans and are thought to be important participants in marine biogeochemical cycling. Of these viruses, cyanophages are considered especially important because they infect and lyse cyanobacteria, which are some of the main primary producers in marine environments. Cyanophages are thought to influence the abundance and diversity of cyanobacterial populations and impart significant mortality, thereby affecting primary productivity and microbial community structure. Despite their ecological relevance, little is known about how environmental factors shape cyanophage abundance and diversity over large temporal and spatial scales. To address this gap in knowledge, seawater samples were collected during …


Factors Influencing Diarrheal Pathogen Presence In Tubewells Of Bangladesh, Kati Anne Ayers Aug 2013

Factors Influencing Diarrheal Pathogen Presence In Tubewells Of Bangladesh, Kati Anne Ayers

Masters Theses

Diarrheal disease pathogens remain a major concern in developing countries as rotavirus is the leading cause of hospitalization of young children worldwide. A recent study has shown shallow groundwater in rural Bangladesh to be contaminated with bacterial and viral pathogens, but found no correlation between rotavirus and any fecal indicator or environmental parameter during the monsoon season of July, 2009. The objectives of this thesis were to examine the non-relationship between pathogens and fecal indicators, as well as to improve the understanding of the seasonal transport of viral pathogens, especially rotavirus, in shallow, sandy aquifers of Bangladesh. This was achieved …


Long Term Impacts Of A Genetically Engineered Microorganism (Gem) And Polycyclic Aromatic Hydrocarbons (Pahs) On Soil Bacterial Communities, Xiaoci Ji May 2013

Long Term Impacts Of A Genetically Engineered Microorganism (Gem) And Polycyclic Aromatic Hydrocarbons (Pahs) On Soil Bacterial Communities, Xiaoci Ji

Masters Theses

Microbes capable of polyaromatic hydrocarbon (PAH) biodegradation can be used to remediate soils contaminated with these persistent pollutants. To monitor in situ PAH-biodegradation, the bioluminescent bio-reporter Pseudomonas fluorescens HK44, containing a lux luminescent gene cassette inserted into its naphthalene degradation operon, was released into PAH-contaminated soil in lysimeters in 1996. Three treatments were imposed: strain HK44 mixed with PAH-contaminated soil (PAH+, HK44+; n=3); strain HK44 mixed with uncontaminated soil (PAH–, HK44+; n=2) and PAH-contaminated soil alone (PAH+, HK44–; n=1). The objective of this study was to assess the long term impacts of these treatments on the indigenous soil bacterial community …


Revealing The Ecological Role Of Gemmatimonadetes Through Cultivation And Molecular Analysis Of Agricultural Soils, Mariam Naomi Fawaz May 2013

Revealing The Ecological Role Of Gemmatimonadetes Through Cultivation And Molecular Analysis Of Agricultural Soils, Mariam Naomi Fawaz

Masters Theses

Bacteria belonging to phylum Gemmatimonadetes are frequently detected in a variety of environments using culture-independent methods. Despite their ubiquity and prevalence, almost nothing is known about their physiology or ecology because so few strains have been isolated. The first objective of this study was to determine the distribution of Gemmatimonadetes within soil aggregates and the response of the relative abundance of Gemmatimonadetes to dry/wet cycling and soil management. The second objective was to analyze the effects of soil management, aggregate size, and atmospheric conditions on cultivability of Gemmatimonadetes. Universal and Gemmatimonadetes-specific 16S rRNA gene primers were used to …


Soil Microbial Community Succession During Cadaver Decomposition, Kelly Lynn Cobaugh May 2013

Soil Microbial Community Succession During Cadaver Decomposition, Kelly Lynn Cobaugh

Masters Theses

Microbes play critical roles in nutrient cycling in terrestrial ecosystems. In particular, microbial decomposition of organic matter is a key step in carbon and nutrient cycling, linking above-ground and below-ground pools. It is well known that the microbial community changes in structure and function following the introduction of organic matter into a terrestrial system. The decomposition of plant litter has been extensively investigated but the decomposition of animal-derived organic matter has often been overlooked. The unique characteristics of animal input are hypothesized to dictate a distinct decomposition process. This study examined the microbial community responsible for decomposition of animal-derived organic …