Document Type

Capstone Project

Comments

Submitted to: William Palm, Ph.D., Director, University Honors Program and Koty Sharp, Ph.D., Director, Center for Economic and Environmental Development, Associate Professor of Biology.

In fulfillment of the requirements for the University Honors Program Capstone.

Abstract

Climate change is affecting our oceans negatively in many ways, such as rising temperatures and increased disease outbreaks. While there are many diseases that are affecting marine organisms, bacteria of the genus Vibrio are present globally and are known to favor warmer waters, which means increasing temperatures will cause an uptick in infections. One species, V. coralliilyticus, has been identified as a pathogen responsible for coral disease and death as well as mortality in rainbow trout, brine shrimp, and Pacific oyster larvae. A possible solution to the rising prevalence of disease is the use of probiotics. One such probiotic candidate species, Pseudoalteromonas rubra, has been isolated from tropical corals in the Indo-Pacific, Pacific, and Atlantic Oceans, with 45 different strains isolated from a variety of substrates, organisms, and seawater. In order to test the effectiveness of P. rubra against V. coralliilyticus in anthozoans, the anemone Exaiptasia diaphana can be used as an analogous organism to corals. During challenge assays with E. diaphana using P. rubra and V. coralliilyticus, P, rubra was shown to prevent mortality when used as a post-Vibrio treatment. Challenge assays were also performed with eastern oyster (Crassostrea virginica) larvae, with P. rubra being effective as a pretreatment, seeing survival rates of up to 99% in larvae that were given V. coralliilyticus after an initial P. rubra dose. Exposure assays using P. rubra were also performed on the algae Tisochrysis lutea to determine if P. rubra will interfere with feeding in oysters. There was found to be no impact on the density of algal cells, indicating that P. rubra will not interfere with oyster feeding. Across the three experiments, P. rubra has been shown to be an effective probiotic when used against V. coralliilyticus. Future work should examine the potential for using in larger scale operations and expand assays to other organisms and pathogens.

Download

Share

COinS