Comparative evaluation of certain organic and inorganic sources of nitrogen for phototrophic growth of marine microalgae

Abstract
Twenty-six species of marine planktonic algae, belonging to 8 taxonomic divisions, were tested tinder axenic-culture conditions for their capacity to grow, under cool-white light, on nitrate, nitrite, ammonium, urea, glycine, D-glucosamine or hypoxanthine as sole nitrogen source. The culture medium was composed of Mediterranean oligotrophic sea water enriched with phosphate, silicate, trace-metal ions and vitamins, and buffered at pH 7.5–80. Each nitrogen compound was tested at a fixed concentration of 500 μg-at. N per litre.