Life Sciences Commons^™

Characterization Of Genes And Pathways Controlling Biofilm Formation In Saccharomyces Cerevisiae, Neha Sarode

Doctoral Dissertations

Biofilms are a mode of growth where aggregated cells adhere to a foreign surface and grow as a complex community. Biofilms have found wide utility in commercial industries, however infections caused by biofilms in clinical settings are a major cause of concern. Understanding molecular details of biofilm formation could help in exploitation or elimination efforts.

We utilize Saccharomyces cerevisiae as a model system to study biofilm formation. S. cerevisiae strain belonging to genetic background Σ [sigma] 1278b is capable of forming biofilms, on low density (0.3%) agar media. When grown at 25°[degree] C for 5 days, it develops into an …

Efficacy Of Biopesticides For Organic Management Of Cucumber Beetles, Mary A. Rogers

Doctoral Dissertations

Organic growers are limited in crop protection techniques for cucumber beetle management. Spotted (Diabrotica undecimpunctata howardi) and striped (Acalymma vitatta) cucumber beetles and are significant pests of cucurbits in the U.S. Feeding results in aesthetic damage and reduction in marketable yields as well as transmission of bacterial wilt that can result in plant mortality. Biopesticides are products formulated from naturally occurring organisms such as fungi and bacteria that are pathogenic or toxic to insect pests. Advantages to these products are that they have low environmental risk, low risk to non-target organisms including mammals and beneficial insects, …

Characterization Of Chemosensing In The Alphaproteobacterium Azospirillum Brasilense , Matthew Hamilton Russell

Doctoral Dissertations

Motile bacteria must navigate their environment in constant search of nutrients to sustain life. Thus they have evolved precise and adaptable sensory systems to achieve this goal, making the navigation system of the model bacterium Escherichia coli the best characterized signal transduction pathway in Biology. However, many bacteria have evolved more sophisticated arsenals for sensing and responding to their environment including chemoreceptors to identify novel attractants in the microenvironment. The diazotrophic alphaproteobacterium Azospirillum brasilense inhabits the soil and colonizes the roots of cereals like rice, corn, and wheat. Like most proteobacterial, A. brasilense encodes multiple chemotaxis-like pathways, 4, of which …

Sulfate Reducing Communities In Aquifer Systems Can Be Reliably Stimulated By Addition Of Complex Nutrients, Matthew Bryan Scholz

Doctoral Dissertations

The disseration presented below is the summation of research into the potential roles of microbial communities associated with aquifers of Bangladesh contaminated with naturally occuring arsenic. These investigations also included experimental microcosm experiments to assess the role of nutrients supplementation of complex carbon sources (molasses), and inorganic sulfate (MgSO4), on both the solubility of arsenic to determine the feasibility of this method for the goal of performing in situ bioremediation. Community structure and functional gene profiling was performed on all samples, as well as detection of community shifts following amendments predicted to encourage the growth of sulfate reducting microorganisms (SRM). …

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 …

Role Of Surface Antigens Of Mycobacterium Spp. In Diagnosis, Ashutosh Wadhwa

Doctoral Dissertations

Mycobacterial species are ubiquitous in nature and a worldwide concern for human and animal health. The major mycobacterial infections in animals are Johne’s disease (JD) and bovine tuberculosis (bTB). Controlling these infections is difficult due to the lack of highly sensitive and sensitive diagnostic test. Currently available diagnostic tests have to be carried out in laboratory settings with well experienced and trained examiners. My goal is to develop a sensitive on-site (in-field) device for diagnosis of Johne’s disease and bovine tuberculosis. The specific aims of this thesis were (1) to review currently-used or recently developed diagnostic tests for mycobacterial infections, …