Comparative growth and carotenoid production in the green microalga Dunaliella salina from marine and continental ecosystems: harnessing environmental diversity for sustainable industrial applications

Abstract

In Morocco, diverse saline ecosystems support both industrial salt production and the growth of Dunaliella salina, a halophilic unicellular green microalga in class Chlorophyceae, and well-known for its applications in aquaculture, cosmetics, food and pharmaceuticals owing to its significant carotenoid-producing potential. This study compares the growth and carotenoid production of six strains (DUN1–DUN6) isolated from salt ponds in southern and central Morocco to identify high-performing local strains. Among these, strains DUN3, DUN4 and DUN5 exhibited exceptional carotenoid accumulation (maximum of ∼18 mg l^–1). Notably, strain DUN5 shows promise for industrial applications, combining high carotenoid yield with a cell density of 2 × 10⁵ cells ml^–1. These findings highlight the potential of D. salina as a sustainable source of beta-carotene. This research advances the sustainable valorisation of Morocco’s saline resources and promotes economic opportunities through the industrial exploitation of this valuable microalga.