Carotenoid Production by <i>Dunaliella salina</i> with Magnetic Field Application

The use of external triggers in microalgae cultivation has emerged as a promising approach to enhance biomass production and biochemical composition. For instance, magnetic fields (MFs) have had their potential to modulate cellular metabolism and physiological responses explored. This study investigated the effects of MF exposure on <i>Dunaliella salina</i> and evaluated its impact on biomass production, pigment synthesis and biochemical composition. The highest biomass concentration (0.59 g L⁻¹) was observed under continuous exposure to 60 mT (MF60-24 h); it represented a 51% increase in comparison with the control. A gradual rise in pH, which reached 10.83, was observed during cultivation. MF exposure also enhanced chlorophyll-a (118%) and carotenoid (95%) concentrations; thus, it improved photosynthetic efficiency and potential oxidative stress responses. The biochemical composition revealed a shift in metabolic pathways after prolonged MF exposure (24 h d⁻¹), decreasing carbohydrate content by 7%, while increasing lipid accumulation by 7%. Scanning electron microscopy (SEM) indicated structural modifications on the cell surface induced by the MF. Therefore, MF applications improve <i>D</i>. <i>salina</i> cultivation and enhance biomass composition for biotechnological applications.