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Articles 1 - 7 of 7
Full-Text Articles in Life Sciences
The Role Cranberry Proanthocyanidins Play In The Primary Attachment Of Bacteria To Surfaces: Bacillus Cereus Model, Anthony Robert Jones
The Role Cranberry Proanthocyanidins Play In The Primary Attachment Of Bacteria To Surfaces: Bacillus Cereus Model, Anthony Robert Jones
Biology Dissertations
The development of a proanthocyanidin (PAC) treatment, along with the understanding of its mechanism of action, would provide an alternative method of preventing attachment to and colonization of surfaces by microorganisms, as well as potentially disrupting preexisting biofilms. The purpose of this research is to examine the role a cranberry proanthocyanidin plays in the primary attachment of Bacillus cereus to an abiotic surface. This technology could be employed in food processing plants where a premium is placed on maintaining a sanitized work environment to prevent product contamination. A biofilm assay showed that a surface treated with proanthocyanidins actually promoted rather …
Identification Of Two Gene Clusters And A Transcriptional Regulator Required For Pseudomonas Aeruginosa Glycine Betaine Catabolism, Matthew J. Wargo, Benjamin S. Szwergold, Deborah A. Hogan
Identification Of Two Gene Clusters And A Transcriptional Regulator Required For Pseudomonas Aeruginosa Glycine Betaine Catabolism, Matthew J. Wargo, Benjamin S. Szwergold, Deborah A. Hogan
Dartmouth Scholarship
Glycine betaine (GB), which occurs freely in the environment and is an intermediate in the catabolism of choline and carnitine, can serve as a sole source of carbon or nitrogen in Pseudomonas aeruginosa. Twelve mutants defective in growth on GB as the sole carbon source were identified through a genetic screen of a nonredundant PA14 transposon mutant library. Further growth experiments showed that strains with mutations in two genes, gbcA (PA5410) and gbcB (PA5411), were capable of growth on dimethylglycine (DMG), a catabolic product of GB, but not on GB itself. Subsequent nuclear magnetic resonance (NMR) experiments with 1,2-(13)C-labeled choline …
The Regulation Of The Icsp Promoter Of Shigella Flexneri By The Virulence Factor Virb, Maria Castellanos, Dustin Harrison, Helen Wing
The Regulation Of The Icsp Promoter Of Shigella Flexneri By The Virulence Factor Virb, Maria Castellanos, Dustin Harrison, Helen Wing
Undergraduate Research Opportunities Program (UROP)
Shigella flexneri is a pathogenic bacterium that causes severe dysentery in humans commonly known as shigellosis. Shigella encodes an outer membrane protease called IcsP. The regulation of icsP expression is under direct control of a transcriptional factor called VirB, which controls the expression of many virulence genes in Shigella. Previous work has shown through deletion analysis of the icsP promoter region that sequences as far as 1368 base pairs upstream of the transcription starting site are important for the regulation of the icsP gene by VirB. However, it is still unclear whether VirB activation requires sequences within the icsP promoter …
Construction Of A Thif Genetic Disruption In Bacillus Subtilis, Kathleen Bradley, Christine Pybus, Ronald Yasbin, Eduardo Robleto
Construction Of A Thif Genetic Disruption In Bacillus Subtilis, Kathleen Bradley, Christine Pybus, Ronald Yasbin, Eduardo Robleto
Undergraduate Research Opportunities Program (UROP)
The goal of our research is to determine whether the level of transcription of a gene is correlated with the level of mutation in that gene. One factor involved in the mutability of a transcribed gene is the ability of the single stranded DNA to form secondary stem loop structures (SLS), in the wake of the transcription bubble, that contain unpaired mutable bases. We are interested in correlating the levels of mutation with transcription in the thiF gene, which is predicted by bioinformatic analysis to be highly mutable. To achieve this goal, Kathleen will first construct a non-polar thiF genetic …
The Effect Of Cody On Stationary Phase Mutagenesis In Bacillus Subtilis, May Yared, Holly Martin, Eduardo A. Robleto, Ronald E. Yasbin
The Effect Of Cody On Stationary Phase Mutagenesis In Bacillus Subtilis, May Yared, Holly Martin, Eduardo A. Robleto, Ronald E. Yasbin
Undergraduate Research Opportunities Program (UROP)
We examine the notion that cells in conditions of stress accumulate mutation is in genes under selection via transcription processes. CodY is a global transcriptional regulator in many Gram positives, including soil and pathogenic microbes. In conditions of exponential growth and when branch chain amino acids and GTP are in abundance CodY acts as a transcriptional repressor of many metabolic operons. This transitional repression saves the cell energy and allows efficient use of resources. In conditions of starvation, CodY relieves repression of genes involved in acquisition of nutrients and degradation of carbon sources (genes under selection). Here, we compare the …
Constructing An Argf- Strain Of Bacillus Subtilis, Allison Faucher, Christine Pybus, Ronald E. Yasbin, Eduardo A. Robleto
Constructing An Argf- Strain Of Bacillus Subtilis, Allison Faucher, Christine Pybus, Ronald E. Yasbin, Eduardo A. Robleto
Undergraduate Research Opportunities Program (UROP)
The goal of our research is to determine whether the level of transcription of a gene is correlated with the level of mutation in that gene. One factor involved in the mutability of a transcribed gene is the ability of the single stranded DNA to form secondary stem loop structures (SLS), in the wake of the transcription bubble, that contain unpaired mutable bases. We are interested in correlating the levels of mutation with transcription in the argF gene, which is predicted by bioinformatic analysis to be highly mutable. To achieve this goal, Allison will first construct a non-polar argF genetic …
Second-Sphere Amino Acids Contribute To Transition-State Structure In Bovine Purine Nucleoside Phosphorylase, Lei Li, Minkui Luo, Mahmoud Ghanem, Erika A. Taylor, Vern L. Schramm
Second-Sphere Amino Acids Contribute To Transition-State Structure In Bovine Purine Nucleoside Phosphorylase, Lei Li, Minkui Luo, Mahmoud Ghanem, Erika A. Taylor, Vern L. Schramm
Erika A. Taylor, Ph.D.
Transition-state structures of human and bovine of purine nucleoside phosphorylases differ, despite 87% homologous amino acid sequences. Human PNP (HsPNP) has a fully dissociated transition state, while that for bovine PNP (BtPNP) has early SN1 character. Crystal structures and sequence alignment indicate that the active sites of these enzymes are the same within crystallographic analysis, but residues in the second-sphere from the active sites differ significantly. Residues in BtPNP have been mutated toward HsPNP, resulting in double (Asn123Lys; Arg210Gln) and triple mutant PNPs (Val39Thr; Asn123Lys; Arg210Gln). Steady-state kinetic studies indicated unchanged catalytic activity, while pre-steady-state studies indicate that the chemical …