Metabolism links nutrient stress and harmful algal bloom formation

Four species of phytoplankton representing important bloom-forming species from three globally important phyla (Bacillariophyta, Haptophyta, and Ochrophyte) were cultured in this study. These species include the cosmopolitan diatom Chaetoceros affinis CCMP159 (isolated from Great South Bay, NY, USA, 1958), the haptophytes Chrysochromulina polylepis CCMP1757 (isolated from the North Sea 1988) and Gephyrocapsa oceanica RCC1303 (isolated from Arachon Bay, France, Jan 1999), and the raphidophyte Heterosigma akashiwo strain CCMP 2393 (isolated from Rehoboth Bay, Delaware, USA). Cultures were grown under three conditions: nitrogen-stress, phosphorus-stress, and replete conditions. Intracellular metabolites were extracted from cultures and analyzed with targeted and untargeted mass spectrometry-based metabolomics methods.