Date of Award
2024
Degree Type
Thesis
Degree Name
Master of Science in Pharmaceutical Sciences
Department
Biomedical and Pharmaceutical Sciences
First Advisor
David Rowley
Abstract
The microbial communities of crustose coralline algae (CCA), a known substrate for coral recruitment, produce bioactive compounds that aid in the physiological processes of larval settlement and metamorphosis. One example is the proposed larval morphogen cycloprodigiosin which is produced by CCA-associated Pseudoalteromonas rubra strains. However, the lipophilicity of this compound limits its water solubility and raises questions regarding its delivery in the marine environment. In this study, we hypothesized that hydrophobic chemical signals are packaged within bacterial membrane vesicles (MVs). A combined genomic and metabolomic approach was used to investigate specialized metabolites produced by CCA-associated P. rubra strains KB1 and CH007. Whole genome sequencing supported the production of prodiginines by both strains. Cell pellets, MVs, and supernatants were collected from cultures harvested at multiple time points and subjected to metabolomic analysis using UHPLC tandem mass spectrometry. Multiple prodiginine metabolites, including prodigiosin, 2-methyl-3-hexyl prodiginine, and cycloprodigiosin, were detected exclusively within the cells and MV fractions. P. rubra MVs further demonstrated antimicrobial activities against a panel of coral-associated Vibrio spp. These results suggest MVs as a delivery mechanism for specialized metabolites that contribute to bacteria-bacteria and bacteria-host interactions.
Recommended Citation
Hill, Margaret, "CHEMICAL INVESTIGATION OF MEMBRANE VESICLES ISOLATED FROM PSEUDOALTEROMONAS RUBRA" (2024). Open Access Master's Theses. Paper 2534.
https://digitalcommons.uri.edu/theses/2534