Outdoor cultivation of Dunaliella salina KU 11 using brine and saline lake water with raceway ponds in northeastern Thailand.

To evaluate the potential of algal biotechnology to replace traditional agriculture in northeastern Thailand, an open raceway cultivation system was developed to produce biomass and beta-carotene. Dunaliella salina KU 11 isolated from local saline soil was cultured in open raceway tanks using brine and saline lake water. Grown in modified Johnson's medium (with 2-3.5 M NaCl), the algae reached a maximum cell density on the fourth day (1.8 × 106 cells mL-1 ). Increasing KNO3 and NaHCO3 from 0.5 and 0.043 g L-1 to 1 and 2.1 g L-1 , respectively, significantly improved the yields of biomass (0.33 g L-1 ) and beta-carotene (19 mg L-1 ). Expected profits for algal production were evaluated, and it was found that this strain was suitable for outdoor cultivation and the developing algal industry in northeastern Thailand could produce high economic benefits (at least $64,120 per year per 0.16 ha).