Rachel Leigh Spiegel, Oxford College of Emory University

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Abstract:

P. minimum, a toxic dinoflagellate found in the Chesapeake Bay, was investigated to determine the degree that lipid composition could be changed with environmental conditions. P. minimum was cultured in CO₂-limited conditions, CO₂-replete conditions, high and low light, and in different concentrations of selenium, in two forms, Na₂SeO₃ and Na₂SeO₄. The CO₂ cultures were obtained from Gary Wickfor's lab. He found that the CO₂-limited culture caused mortality of scallops in 24 hours while the CO₂-replete culture caused mortality in 4 days. Lipid composition in the CO₂-limited cultures indicates no change in sterols other than the loss of phytol but does indicate a change in the fatty acid composition. In the selenium experiment, only the high light cultures were filtered for analysis as the low lights had not reached a high enough concentration. Preliminary results indicate that Se has an effect on growth rates of P. minimum. Lipid composition, including 18:5n3 levels, did change with Se concentration.