Author Type

Graduate Student

Date of Award

2024

Document Type

Dissertation

Publication Status

Version of Record

Submission Date

October 2026

Thesis/Dissertation Advisor [Chair]

Louda, J. W.

Abstract

Cyanobacteria are ancient prokaryotes that use photosynthesis and an accumulation of other adaptations to dominate aquatic ecosystems around the world. They are thus major contributors to biogeochemical cycling, a threat to human and environmental health, and an intriguing source for novel chemistry. We begin by providing an overview of bloom-forming cyanobacteria and their many toxic metabolites. We then discuss the characterization of some abundant extracellular pili of Microcystis aeruginosa, reporting a 2.4 Å cryoelectron microscopy pilus structure, revealing a novel class of pili that we have termed cyanobacterial tubular (CT) pili. The CT pili in M. aeruginosa were determined to be multi-functional, with a primary role in networking cells and enhancing colony formation, but also in controlling colony buoyancy, enriching iron, and accumulating toxins in the extracellular mucilage. Lastly, we explore the potential of heavy-labeling cyanobacterial cultures for the sake of isolating natural products that can be studied by vibrational spectroscopic imaging. The vibrational spectra of three classes of cyanopeptides along with their heavy-labeled counterparts are reported, and Density Functional Theory calculations are used to describe mode character, clarifying some unexpected changes in vibrational spectra upon heavy-labeling. As a whole, this work offers new insight into cyanobacterial physiology as well as a means to study cyanopeptides with imaging techniques and stable-isotope labeling.

Extent

170 p.

Comments

Includes bibliography.|Dissertation (PhD)--Florida Atlantic University, 2024.|FAU Electronic Theses and Dissertations Collection|Includes bibliography.

Identifier

FA00014490

Format

pdf

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