Development of highly effective growth strategies aiming at improving the content of carotenoids in Dunaliella salina IFDSAL-JY215†

Dunaliella salina is the most promising natural source of β-carotene, presenting itself as a valid alternative to traditional chemically synthesized carotenoids. Microalgal pigments present several advantages compared to their synthetically produced counterparts, revealing, for instance, higher bioaccessibility. In the present study, a central composite rotatable design and a central composite design were employed to maximize β-carotene production through the optimization of 4 cultivation variables (salinity, airflow, and the nitrogen and phosphorus concentration in the growth medium). The optimal conditions found for β-carotene production were 64 PSU of salinity, an airflow of 500 mL min⁻¹, and a nitrate and phosphate concentration of 6 mmol L⁻¹ and 0.4 mmol L⁻¹, respectively. When compared to the standard conditions, optimized cultures resulted in an improvement in the β-carotene concentration of around 88%. Concomitantly, a biomass concentration increase of 132% was observed for D. salina, from 0.93 g L⁻¹ – under standard conditions – to 2.16 g L⁻¹, under the optimal conditions. The microalga's carotenoid profile was also found to be positively influenced by the optimization process.