Microbiology Commons^™

Exploring Anaerobic Reductive Dechlorination At Low Ph Environments, Yi Yang

Masters Theses

Chlorinated aliphatic hydrocarbons (CAHs), such as tetrachloroethene (PCE) and trichloroethene (TCE), are ubiquitously pollutants in aquifer sediments and groundwater due to their heavy usage in industry and inappropriate disposal in the last century. Among about 1300 NPL (National Priorities List) sites, PCE and TCE are the two most frequently detected hazardous contaminants.

Engineered bioremediation, including biostimulation and bioaugmentation, is a promising technology to clean those PCE and/or TCE contaminated sites. However, in many contaminated groundwater systems and hazardous waste sites, pH can be lower than 5 to 6. And release of HCl (strong acid) from anaerobic reductive dechlorination may lower …

Fatty Acid Synthase 1 In Candida Albicans Virulence And The In Vitro Effects Of Fluconazole, Tetracycline In Combinatorial Therapy, Marissa Mandy Rodrigues

Masters Theses

Candida albicans, the causative agent of superficial and invasive mycoses, is a significant fungal pathogen associated with high mortality rates and considerable health-related costs. The most effective class of antifungals used for the treatment of candidiasis includes polyenes, echinocandins and azoles. However with the emergence of resistant strains, new antifungals are warranted for the effective treatment of candidiasis. Genes involved in biosynthetic enzymatic pathways that regulate metabolic processes are important for the survival of pathogenic fungi and can thus be exploited for the development of better antifungals. Fatty acid synthase 1, which is involved in the de novo biosynthesis of …

Genetic Basis Of Flocculation In Azospirillum Brasilense., Priyanka Satish Mishra

Masters Theses

Azospirillum brasilense is a class of rhizobacteria capable of nitrogen fixation, root colonization and hence promoting host plant growth. The bacteria posses cell interaction behaviors like clumping and flocculation that contribute the survival of the organism in nutrient limited conditions. Change in the cell surface adhesive properties allows the cells to progress from free swimming to clumping and finally flocculation. Less is known about the genetic regulation of these processes with flcA being the only transcriptional regulator known so far to directly control flocculation. Recent evidence suggesting that Che1, a chemotaxis like signal transduction pathway controls the cell behavior clumping …

The Effects Of Nutrient Limitation And Cyanophage On Heterotrophic Microbial Diversity, Claire Elyse Campbell

Masters Theses

Marine viruses are critically important in the regulation of biogeochemical cycles and host microbial communities. In this study, we tested whether the indirect effects of virus predation on a phototroph (i.e., Synechococcus) affected the composition of co-occurring heterotrophic bacteria under nitrogen and phosphorus limitation in long-term chemostat experiments. Using 454 Titanium barcoded pyrosequencing of the 16S rRNA gene, microbial diversity and technical (i.e., sequencing) reproducibility were assessed for nine individual chemostats across five different time points. A total of 325,142 reads were obtained; 194,778 high-quality, non-cyanobacterial sequences were assigned to 110 OTUs. Our results show high reproducibility …

An Analytical Survey Of A Biotinylated Bacteriophage System For Quantifying Transduction Events In Natural Ecosystems, Thomas James Mead

Masters Theses

Bacteriophage transduction events play a contributive role in bacterial gene diffusion in ecosystems comprised of natural microbial populations. The rate at which these phage-mediated genetic transfers occur in wastewater ecosystems is not well understood. This work describes the effectiveness of a genetically engineered biotinylated bacteriophage T4 system as a tool for examining transduction event rates and compositions in environments that pose increased risk of antibiotic resistance proliferation.

Antibiotic use has steadily increased over the past century, giving rise to antibiotic resistance in microorganisms. Agricultural, medical, and industrial use of antibiotics produces waste teeming with residual antibiotic compounds that are collected …