Palau, Jackie Lin

Microbial partners provide beneficial and detrimental functions to their hosts and other microbes through the exchange of metabolites and info chemicals. Developing an understanding of these micro-interactions has considerable implications for human health, agriculture, and ecosystem protection. Here, the microbial interactions of two important marine organisms: the Forcepia sp. sponge, a source of the potential anticancer compound, lasonolide A (LSA), and Pyrodinium bahamense, a dinoflagellate which produces the potent neurotoxin, saxitoxin, were investigated. Chapter 1 introduces marine microbial interactions, their importance in the function of organisms and ecosystems, and their applications in human health, agriculture and ecosystem production. Chapter 2 describes the identification and capture of the lasonolide biosynthetic pathway from a metagenomic fosmid library. This chapter also describes the assembly of the pathway into an expression vector and attempts to sustainably produce LSA through heterologous expression. Chapter 3 describes the identification and characterization of the bacterial associates of Pyrodinium bahamense, a toxin producing dinoflagellate found in the northern Indian River Lagoon. This chapter also describes potential chemical and molecular interactions occurring between P. bahamense and its associated cultivable bacteria. Chapter 4 describes the investigation into the effects microbial associates have on the physiology of P. bahamense. The completion of this work further describes microbial interactions occurring in marine environments, their influences and functions in the physiology and evolution of marine organisms, and the tools available for their investigation and utilization for human and ecosystem benefit.