Effect of nitrate concentration on growth and pigment synthesis of Dunaliella salina cultivated under low illumination and preadapted to different salinities

A wild strain of Dunaliella salina was isolated from a solar evaporation sa lt-pond in Araya (Estado Sucre, Venezuela) and grown in batch culture using relatively low illumination (80 mu mol photon m(-2) s(-1)). After the alga had been adapted to various salinities (9, 14, 21% w/v NaCl), the influenc e of nitrate concentration (882, 435, 212 mu mol L-1 N) on growth rate and chlorophyll a and total carotenoid concentrations was measured. Low nitrate concentration negatively affected growth, but enhanced carotenoid accumula tion. A slight increase in carotenogenesis was also observed in alga grown at the highest salinity. There were no significant additive or synergistic effects of salinity and nutrient concentrations on the concentrations of ch lorophyll a or total carotenoid.