Organismal Biological Physiology Commons^™

The Stringent Response In Pseudomonas Aeruginosa Influences The Phenotypes Controlled By The Gac/Rsm System, Michael Shawn Hooker

Electronic Theses and Dissertations

Pseudomonas aeruginosa is a ubiquitous, opportunistic pathogen that causes acute and chronic infections. Infection is typically initiated via motile and virulent strains. After exposure to stressors, acute infections make both genotypic and phenotypic switches to a chronic, sessile strain. This is due to intricate regulatory networks directing gene expression in response to stressors. One network, GacA/GacS, has been established to control virulence factors. The stringent response of bacteria is mediated by alarmones produced primarily by RelA which responds to starvation.

To study the effect of the stringent response on the virulence switch. A series of experiments were run in both …

Characterization Of Phycoerythrin Physiology In Low-Light Adapted Prochlorococcus Ecotypes, Kathryn H. Roache-Johnson

Electronic Theses and Dissertations

The marine cyanobacteria Prochlorococcus and Synechococcus are the most abundant phototrophs in the oceans. They cohabit the oligotrophic ocean and thus have coevolved together, yet they have distinctly different methods for harvesting light. Synechococcus, like other cyanobacteria, possess phycobilisomes with various combinations of phycobiliproteins to capture wavelengths of light not otherwise available to chlorophyll. Prochlorococcus lack phycobilisomes and use divinyl chlorophyll b (Chl b2) as their primary accessory pigment to divinyl chlorophyll a (Chl a2) to capture light energy. In addition to the divinyl chlorophylls, Prochlorococcus has genes associated with the phycobiliprotein phycoerythrin (PE), the role of which is still …