Total Phenolic Content and Antioxidant Capacity of <i>Dunaliella salina </i>Were Cultivated Under Stress Conditions on Salt Field Media

Abstract

<i>Dunaliella salina</i> (<i>D. salina</i>) is a unicellular green microalga with a high β-carotene content and bioactive compounds that is essential for any study of the application of microalgae. The current research aimed to evaluate total phenolic content, and antioxidant capacity of <i>D. salina</i> CCAP 19/18 strain in RM1 and RM2 salt field media under various stress conditions including natural light, high salinity, and nitrogen starvation. As a result, after 17 days of being enrichment, in the RM1 medium, there was no significant difference in phenolic content under natural light, high salinity, and nitrogen starvation stresses, with p = 0.305. Similarly, the antioxidant capacity had no significant difference, which was p = 0.105 (natural light with high salinity), and p=0.428 (nitrogen starvation with high salinity). While in RM2 medium, the phenolic content and antioxidant capacity under nitrogen starvation stress far exceeded that of natural light and high salinity, with respective figures being 157.147 fg acid gallic/cell and 600.443%/cell and these figures had a significant difference (p<0.05). As a consequence, we could choose an appropriate medium for cultivating and harvesting algae in a large-scale pilot. These true potential extract ingredients in algae are fascinating for cosmetic industries or used for various health benefits such as nutraceuticals and medications against damaging causes, particularly free radicals.