Potential for Carotenoid and Other Bioproducts Production by a Brazilian Dunaliella salina Isolate Using a High Photon Flux Density Strategy

ABSTRACT Dunaliella species are among the most significant biological sources of carotenoids, notably beta‐carotene. Given that chemical synthesis offers a more cost‐effective alternative to biotechnological cultivation, optimizing production strategies is essential for economic viability. This study investigated the optimization of bioproduct synthesis in a Brazilian strain of Dunaliella salina by evaluating the effects of high photon flux density (PFD) and temperature under low‐salinity conditions (1 mol L −1 NaCl) to facilitate downstream processing. Batch cultivations were conducted at 26°C across a PFD gradient ranging from 100 to 2000 µmol photons m −2 s −1 , with additional cultivations performed at 30°C under maximum irradiance. The results demonstrated that increasing PFD to 2000 µmol photons m −2 s −1 significantly enhanced metabolic performance, yielding a 25% increase in biomass concentration, a 62% rise in biomass productivity, and an 82% surge in total carotenoid production. Furthermore, carbohydrate content increased by 61%, whereas lipid levels remained stable, exhibiting a fatty acid profile conducive to biodiesel production. The temperature variation up to 30°C had no effect on biomass concentration or biomass composition, affecting only the fatty acid composition. These findings underscore the robust potential of this strain for the large‐scale biotechnological production of carotenoids and other high‐value compounds within a biorefinery framework.