Blue-Red LED wavelength shifting strategy for enhancing beta-carotene production from halotolerant microalga, Dunaliella salina.

In the present study, to improve the photosynthetic betacarotene productivity of Dunaliella salina, a blue-red LED wavelength-shifting system (B-R system) was investigated. Dunaliella salina under the B-R system showed enhanced density and beta-carotene productivity compared to D. salina cultivated under single light-emitting diode light wavelengths (blue, white, and red light-emitting diode). Additionally, we developed blue light-adapted D. salina (ALE-D. salina) using an adaptive laboratory evolution (ALE) approach. In combination with the B-R system applied to ALE-D. salina (ALE B-R system), the beta-carotene concentration (33.94 ± 0.52 μM) was enhanced by 19.7% compared to that observed for the non-ALE-treated wild-type of D. salina (intact D. salina) under the B-R system (28.34 ± 0.24 μM).