Effects of arsenic on the organic component of the alga Dunaliella salina

The unicellular marine alga, Dunaliella salina 19/30 was grown in seawater containing an inorganic arsenic concentration (Na₂HAsO₄) up to 2000 mg dm⁻³. The cells survived even at 5000 mg dm⁻³. The arsenic concentration of the cells increased with an increase of the surrounding arsenic concentration. Arsenic in D. salina was also greatly affected by addition of phosphorus. The arsenic‐tolerance behavior of D. salina seemed to suggest that the algae have a function to prevent accumulation of inorganic arsenic by increasing the β‐carotene, fatty‐acid (C_18:1, C_18:3) and water‐extractable carbohydrate content in the cells. Arsenic accumulation also rose steadily with an increase in the nitrogen concentration in the medium.