The study looked at how Dunaliella salina algae grow and produce pigments in different nitrate concentrations. Higher nitrate levels helped the algae grow, while lower levels were better for carotene accumulation. Nitrate was used more in the higher concentration medium. Phosphate use was similar in both media. Chlorophyll levels initially increased but then decreased, while carotene levels did the opposite. The total carotene concentrations were similar in both media.