LAUSR

The production of fucoxanthin and fatty acids in Conticribra weissflogii has been examined, but the role of elements like phosphorus in their mutualistic interactions is not well understood. To fill this gap, our study utilized potassium dihydrogen phosphate (KH2PO4) as a source of phosphorus to examine its impact on the synthesis of fucoxanthin and fatty acids in C. weissflogii. Our findings revealed that at a phosphorus concentration of 10 mg L−1, the cell density (9.5 × 105 cells mL−1), carotenoid concentration (1.67 mg g−1), fucoxanthin concentration (0.91 mg L−1), and fucoxanthin content (1.33 mg g−1) were maximized. Additionally, at a phosphorus concentration of 20 mg L−1, cell dry weight (0.76 ± 0.08 g L−1), total fatty acid content, saturated fatty acids, and unsaturated fatty acids were all at their highest levels, making this concentration optimal for EPA accumulation. In conclusion, manipulating the phosphorus concentration can enhance the levels of fucoxanthin and unsaturated fatty acids in C. weissflogii, offering valuable insights into the co-production of these two high-value compounds within this species.