The Roles of Microcystin and Sulfide in Physiology and Tactic Responses of Pathogenic and Non-Pathogenic Mat-Forming Cyanobacteria

Authors

Abigael C. Brownell, Florida International UniversityFollow

Document Type

Thesis

Degree

Master of Science (MS)

Major/Program

Biology

First Advisor's Name

Laurie L. Richardson

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Miroslav Gantar

Third Advisor's Name

Eric von Wettberg

Keywords

cyanobacteria, black band disease, hot springs, physiology, microcystin, sulfide

Date of Defense

3-24-2014

Abstract

Planktothricoides raciborskii and Roseofilum reptotaenium are physiologically similar, yet ecologically distinct organisms found in a hot spring outflow and coral black band disease (BBD), respectively. The aim of this study was to elucidate the relationship between R. reptotaenium and sulfide in BBD, to compare microcystin (MC) production in response to environmental factors, and to determine chemotactic responses to MC and sulfide by the two organisms. Results showed that the pathogenicity of R. reptotaenium in BBD is dependent on sulfate-reducing bacteria as secondary pathogens. Roseofilum reptotaenium produced significantly more MC than P. raciborskii, as measured using ELISA. Roseofilum reptotaenium was negatively chemotactic to sulfide, determined using horizontal and vertical gradients in agar, while P. raciborskii was not affected. Neither cyanobacterium was chemotactic to MC in the agar assays. The ecophysiology of P. raciborskii and R. reptotaenium in relation to MC production and response to sulfide reflected their pathogenic versus non-pathogenic status.

Identifier

FI14040886

Recommended Citation

Brownell, Abigael C., "The Roles of Microcystin and Sulfide in Physiology and Tactic Responses of Pathogenic and Non-Pathogenic Mat-Forming Cyanobacteria" (2014). FIU Electronic Theses and Dissertations. 1364.
https://digitalcommons.fiu.edu/etd/1364