Effects of phosphorus on algal growth in Picochlorum oklahomense

Abstract

In recent observations, select fertilizers have been modified to include limited phosphorus levels in effort to reduce algae production in bodies of water. Previous studies have shown that a higher phosphorus concentration leads to a higher rate of algae production (Junlei and Xiaoxia 2016). We wished to conduct our own experiment with a newly researched species of algae (Picochlorum oklahomense) to investigate if the results would be similar to other studies. We predicted that there would be a direct relationship between phosphorus concentration and algal growth, with the algae production increasing as the levels of phosphorus increased. Using photobioreactors to grow algae, we added an additional 32 μL of sodium phosphate to our growth solutions in half of the trial bottles and measured the initial and post-trial algae cell count for all bottles after one week. After completing our trials, our data indicated that sodium phosphate had a negative impact on algae growth, and thus did not support our initial hypothesis. In both trials, when 32 μL of sodium phosphate was added, the algae growth rate decreased.