| dc.description.abstract | It is well known that Dunaliella is a great natural source of β-carotene which is a valuable compound, a pro-vitamin A supplement, a health food product, food and cosmetics additive. However, β-carotene accumulation in Dunaliella cells relies much on growth conditions and nutrient components. Set of experiments was conducted to study and determine the optimum high light stress regimen for Dunaliella salina to achieve the highest carotenoids induction. Three D. salina strains (D. salina CCAP 19/18, D. salina A9 and D. bardawil) were cultured in MD4 1.5M medium under stress condition of different regimens during 16 days after the first phase of exponential phase: a cycle of three-day at 800 μmol.photons/m2/s and one day at 50 μmol.photons/m2/s, a cycle of one day at 800 μmol.photons/m2/s and three-day at 50 μmol.photons/m2/s and all-time stress at 800 μmol.photons/m2/s. Total carotenoids were analyzed. Moreover, the antioxidant capacities and total phenolic contents of the algal carotenoid extract were also evaluated. The obtained result revealed that all three D. salina strains produced the highest concentration of total carotene under all-time stress regimen of 800 μmol.photons/m2/s, and D. salina CCAP had higher total carotenoid contents than D. salina A9 and D. bardawil in all stress conditions.
Keywords: Algae, antioxidant, carotene, Dunaliella, phenolic. | en_US |
