Exploration of the Role of Microbiome Structure, Metabolism, and Modification in Black Band Disease Etiology

Authors

Patricia WaikelFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Biology

First Advisor's Name

Mauricio Rodriguez-Lanetty

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Laura Serbus

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

John Berry

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Timothy Collins

Fourth Advisor's Committee Title

Committee Member

Keywords

black band disease, microbiome, microbial metabolism, coral disease, dimethylsulfoniopropionate, Exaiptasia pallida, bioinformatics

Date of Defense

9-18-2020

Abstract

The coral microbiome plays an integral role in coral health. Modification of the microbiome is thought to alter susceptibility to disease. Black Band Disease (BBD), is polymicrobial, mat forming, and affects reef building coral globally. Dominated by the cyanobacterium Roseofilum reptotaenium, it has been noted to increase in virulence with increasing temperatures, making BBD of particular concern in the face of climate change-induced warming seas. The active sulfur cycle of BBD makes dimethylsulfoniopropionate (DMSP), a widely available source of sulfur in the marine environment, of particular interest in the study of BBD. Traditional infection studies require field collection and subsequent maintenance of corals in aquaria, often including lengthy acclimation times, making the identification of a model system for studying BBD timely. I aimed to explore the role of DMSP metabolism in BBD, investigate the suitability of the tropical sea anemone Exaiptasia pallida as a model system for studying BBD, and examine modification of the host and pathogen microbiomes during a BBD challenge. These aims were accomplished by metagenomic analysis and bacterial challenges of E. pallida combined with high throughput 16S rRNA sequencing by Illumina MiSeq. I discovered that DMSP-metabolizing taxa and genes related to DMSP metabolism are present in BBD, suggesting DMSP metabolism by the BBD microbial consortium possibly influencing recruitment of pathogens and promoting the production of toxic microcystin and sulfide. I have demonstrated in this study that the tropical anemone E. pallida is susceptible to BBD across a range of temperatures, symbiotic states, and symbionts hosted, making it a strong candidate model system for studying this disease. Further, susceptibility may be influenced by symbiotic state and fluctuation in virulence of BBD over time. Modification of host and pathogen microbiomes during BBD challenge studies revealed recruitment of taxa from the host microbiome to the disease consortium and loss of taxa from both, providing a foundation for future studies to focus on determining how these specific taxa influence virulence of the disease and susceptibility of the host. Taken together, these findings add to our understanding of the role of microbiome structure, metabolism, and modification in the etiology of this disease.

Identifier

FIDC009186

Recommended Citation

Waikel, Patricia, "Exploration of the Role of Microbiome Structure, Metabolism, and Modification in Black Band Disease Etiology" (2020). FIU Electronic Theses and Dissertations. 4601.
https://digitalcommons.fiu.edu/etd/4601