GROWTH AND ACCUMULATION OF TOTAL CAROTENOIDS IN TWO STRAINS OF Dunaliella salina Teod. (CHLOROPHYCEAE) FROM THE NORTHERN AND CENTRAL COAST OF PERÚ

Abstract

In order to know the dynamics of growth and accumulation of total carotenoids in two strains of Dunaliella salina from the northern (Colan) and central (Chilca) coast of Peru, both strains were cultured during 40 days in controlled laboratory conditions, at 25±2°C, with 150 mol m-2 s-1, without aereation. The strains were grown in two culture media with two different salinities: a modified Johnson medium with addition of 15 and 23% NaCl and a Provasoli enriched seawater medium with 12.5 and 20% NaCl. A period of exponential growth during the first 5 days was observed in both strains, followed by a slow linear growth phase and a stationary phase which lasted until the end of the experiment (day 40). The maxima cellular densities were obtained in the modified Johnson medium at 15% NaCl in both strains, being higher in Chilca (2.2x106 cell mL-1) than in Colan (1.6x106 cell mL-1). The accumulation of total carotenoids per volume was similar in both strains but different in both media; the highest values were obtained in the Provasoli medium with 20% NaCl (13.3± 2.9 mg L-1, Colan and 10.6± 2.5 mg L-1, Chilca). On the contrary, the total content of carotenoids per cell was different in both strains and media; the highest values were obtained in the Provasoli medium with 20% NaCl (110.9± 0.7 and 58.7± 1.3 pg cell-1 in the strains Colan and Chilca, respectively)