A New Shifting Strategy in Flashing Light Based on the Cell Growth Curve to Enhance β-carotene Biosynthesis in Dunaliella salina.

Microalgae Dunaliella salina has been recognized as an effective source of β-carotene. To elevate the productivity of this species, light has been served as an important induction factor, in this regard, a new idea was inspired as designing a red-to-blue wavelength shifting system based on the growth rate and cell behavior. A photobioreactor was exposed to two panels of flashing red and blue LEDs. At the commencement of the stationary phase, the wavelength shifting was applied and red LEDs were replaced with blue ones. Maximum β-carotene content of 10 mg.g-1 was obtained; at least 300% higher than the content in the controlled system (flashing red and blue light to the end of growth).