Bacterial associates of Pyrodinium bahamense isolated from the Indian River Lagoon
Pyrodinium bahamense is a toxic dinoflagellate with a well-documented history of recurrent harmful algal blooms (HABs) in the northern Indian River Lagoon (NIRL) system. P. bahamense produces saxitoxin, a potent neurotoxin responsible for paralytic shellfish poisoning (PSP) which can result in paralysis and death by asphyxiation when consumed in sufficient quantities. Interactions between bacteria and algae within harmful algal blooms are now recognized to play important roles in bloom formation, duration, and toxicity. Bacteria within a HAB can regulate the bloom through mutualistic, commensal, or antagonistic activities. The identity of bacteria associated with IRL P. bahamense and their potential interactions are under-investigated compared to other PSP-producing dinoflagellates. Accordingly, the current study aimed to 1) determine the composition and diversity of the bacterial flora associated with P. bahamense from algal-bacterial co-cultures and natural populations in the IRL and 2) investigate potential interactions between P. bahamense and marine bacterial species through genomic analysis of cultivable bacteria. The results of this study provide a basis for future work to determine how changes in bacterial abundance and chemistry influence P. bahamense physiology as well as bloom formation, magnitude and collapse.