Karlena Brown, Delaware Valley College

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Abstract:

The purpose of this research experiment was to analyze and determine the steady-state growth and elemental ratios of a marine diatom, Thalassiosira pseudonana, grown in a turbidostat when both nitrogen and phosphorus nutrients were varied in solution at non-limiting levels. Nitrogen as nitrate and phosphorus as phosphate concentrations were provided to the turbidostat cultures in different ratios. Direct measurements of nitrogen and phosphorus in the cells were not available as of this report, but indirect measurements based on the difference in the nitrogen and phosphorus concentrations in the media and culture vessels indicated an increase in nitrogen and phosphorus of the biomass with an increase in the nitrogen and phosphorus of the media. Variation in phytoplankton nutrient concentrations may play a role in nutrient transfer and the nutrition of higher trophic levels.