dunaliella

Dunaliella is a genus of unicellular, green microalgae found in highly saline environments around the world, including salt lakes, coastal brine pools, and solar saltworks. The cells are typically small, motile, and lack a rigid cell wall, being surrounded by a flexible plasma membrane. Most species are biflagellate, using two anterior flagella for movement. The organism is photosynthetic, containing chlorophylls a and b in a single plastid, and storing energy as starch.

Dunaliella is exceptionally halotolerant, thriving at salinities near or at saturation, and it often prospers under high light and nutrient limitation. In response to stress, many species synthesize and accumulate large amounts of beta-carotene and other carotenoids, which can color the cells orange to deep red. This carotenoid production is a major focus of commercial cultivation.

The taxonomy of Dunaliella places it among the green algae (Chlorophyta); the genus has multiple species, with Dunaliella salina (also called Dunaliella bardawil in some taxonomic treatments) among the most studied. Placement within higher taxonomic groups has varied among authorities, but it is widely treated as a chlorophyte.

Ecologically, Dunaliella contributes to primary production in saline systems and serves as a source of carotenoids for various commercial applications. Cultured strains are used to produce natural beta-carotene for nutritional supplements, animal feed, and cosmetics, and they are also studied for understanding osmoregulation and carotenoid biosynthesis in extreme environments.