Total carotene, carbohydrate and lipid signal analysis of Dunaliella salina strains

Abstract

Beta-carotene is a terpenoid pigment that is highly valuable due to its nutritional benefit as a precursor of vitamin A and its antioxidant properties. Dunaliella salina and D. bardawil (D. Salina var.bardawil) are well-known microalgae accumulating high levels of β-carotene under growth-limiting conditions. Concentration of β-carotene is different between Dunaliella salina strains. Therefore, the aim of this study was to select Dunaliella salina strains for highest total carotene among 8 local strains (J, K, M, N, O, P, Q, R) and 2 imported strains (D. Salina CCAP 19118 and D. Salina var.bardawil) which were cultured in seawater medium MD4 (Tran et al, 2014) with 1.5 M NaCl. Then they were stressed at 4.0 M NaCl at the stationary phase for carotene accumulation. Total carotene, chlorophyll, cell density (cell count and optical), lipid signal, total carbohydrate and antioxidant capacity content were analyzed. The result obtained revealed that D. bardawil (the imported strain) has the highest concentration of total carotene per cell, and no local strains provide high carotene in current culture conditions compared with the imported strains. Therefore further culture and stress conditions needed to be investigated to optimize carotene of the local strains for carotene production.

Keywords: Algae, carotene, chlorophyll, cultivation, Dunaliella.