ABSTRACT
We studied the effect of salt concentration on the growth and carotenogenesis in two Chilean strains of Dunaliella salina, CONC-006 and CONC-007, cultivated in two media of different chemical composition J/l and PES, under controlled laboratory conditions. Growth rates, k (div day-1), intrinsic production rates of total carotenoids per unit time rcar (day-1), maximum levels of total carotenoids, K (mg l-1), and maximum production of total carotenoids per unit time, rK/4 (micrograms l-1 day-1) were estimated from growth and carotenogenesis data. The highest maximum productivity of total carotenoids was 978 micrograms l-1 day-1 obtained in CONC-007 at 25 percent NaCl, and the lowest 15 micrograms l-1 day-1, in CONC-006 at 30 percent NaCl, both growing in PES medium. CONC-007 showed the highest growth rates, 0.76 and 0.65 div day-1, at the lowest salt concentration (5 percent) in PES and J/1, respectively. On the contrary, the strain CONC-006 exhibited a different growth pattern in both media. Its maximum growth rate in J/1 was 0.37 div day-1 at 20 percent NaCl, and in PES, 0.53 div day-1 at 5 percent NaCl. According to these results, the best integration of growth and carotenogenesis in CONC-007 was obtained at 15 percent NaCl in J/1 from 10 to 25 percent NaCl in PES and in CONC-006, from 5 to 20 percent NaCl in J/1 and from 5 to 10 percent NaCl in PES