The purpose of the present work was to study the potential biotechnological use of Dunaliella species isolated from a hypersaline lake in Turkey. Dunaliella spp. grown in Johnson's medium were isolated and their glycerol production was studied in a batch system in order to determine the optimal conditions required for the highest glycerol accumulation. In the experiments performed with four newly isolated Dunaliella spp., the maximum glycerol accumulation was obtained at 20% NaCl concentration, and pH 6 (for strains T1 and T2) and pH 9 (for strains T3 and T4). Biomass production by strain T2 was significantly higher that by the other strains but the highest glycerol production in broth was obtained by strain T1 followed by strain T2. Strain T1 showed high glycerol production, i.e. 452.57 mu g/ml of culture broth at 20% NaCl concentration, The highest glycerol accumulation on both dry weight and cell basis was obtained with strain T1, followed by strains T3 and T4 (55.01, 50.16, and 40.23 mu g/10(6) cells (or pg/cell), respectively) at 25% NaCl concentration. When the high initial inoculum concentration was used at 25% NaCl concentration, strain T1 had the shortest (approximately 10-15 days) lag period. This study shows that the isolated strains T1 and T2 can be used for glycerol production because of their high productivity. (c) 2008 Elsevier Ltd. All rights reserved.