International Journal of Applied Science and Technology Vol. 3 No. 4; April 2013 118 Identification of Dunaliella Viridis Using its Markers 1 Duc Tran*, 2 Clifford Louime 1 Trung Võ, 3 Mario Giordano 4 Sixto Portilla, 1 Nguyen Doan 1 Dat Tran, 1 Truc Mai, 5 Le Bui 1 School of Biotechnology International University Thu Duc Dist., VNU-Vietnam 2 Florida A and M University College of Engineering Sciences Technology and Agriculture FAMU BioEnergy Group Tallahassee, FL 32307 USA. 3 Dipartimento di Scienze Della Vita e Dell’Ambiente (DISVA) Università Politecnica Delle Marche Via Brecce Bianche, 60131 Ancona Italy 4 Center for Estuarine Environmental and Coastal Oceans Monitoring Dowling College, 150 Idle Hour Blvd Oakdale, New York 11769 5 Department of Biology University of Science, VNU Vietnam. Abstract The phylogenetic position and taxonomic status of the green alga Dunaliella viridis was investigated based on internal transcribed spacer (ITS) markers. The alga was isolated from saltern in Vinh Hao, Binh Thuan province, Vietnam. Independent phylogenetic trees of ITS1 and ITS2 sequences revealed that the alga belongs to the clade of Dunaliella viridis. The salinity for optimal growth of the alga was 2M NaCl, which was much lower than the original sampling site (4M NaCl). This tolerance to a wide range of salinity may provide distinct advantages to Dunaliella viridis over its competitors in natural environments. Further physiological and biochemical characteristics of this strain will need to be investigated in order to assess its potential for algal biomass production and other applications such as beta-carotene, carbohydrate, lipid and protein for feed, food, aquaculture and biofuels, including opening new search for other Dunaliella species. Key Words: Algae, biotechnology, carotene, Dunaliella, ITS, phylogenetic tree. Introduction Unicellular green algae Dunaliella belong to the Chlorophytes (Ginzburg 1987, Pick 1992, Oren 2005). The algae was first described by Dunal in the 1830s (Dunal 1838), but it was not until 1905 that the name Dunaliella was given by Teodoresco (Teodoresco 1905). There are currently 23 recognized Dunaliella species (Massjuk 1972, Pick 1992, Oren 2005). Dunaliella salina TEODORESCO is the type species of the genus, whose vegetative cells are capable of turning red under stress environments such as high irradiance, high salinity, or low nutrient concentrations (Teodoresco 1905&1906, Hamburger 1905, Labbe 1925, Lerche 1937). ____________ *Corresponding Author