Light quality management in Spirulina cultivation to enhance biomass and high-value chemicals production

Spirulina (Arthrospira platensis) is a blue-green alga commonly used in various supplements due to its high protein, fatty acids, vitamins, minerals, and bioactive pigments like phycocyanin. Its growth and biochemical composition are influenced by light. Thus, this study aimed to examine the effects of different LED light wavelengths on biomass and biochemical composition of the Spirulina strain BP. Cells were grown under white, red, yellow, green, and blue lights at 100 µmol photons m-2 s-1 and 35°C for 7 days. The results demonstrated that the biomass productivity was 0.31 ± 0.01 g L-1 d-1 under red light and 0.26 ± 0.01 g L-1 d-1 under yellow light, which was similar to the control (white light, 0.26 ± 0.02 g L-1 d-1). Whereas blue light caused the reduction of biomass productivity (0.08 ± 0.02 g L-1 d-1) but increased in phycocyanin contents by 1.5 times compared to the control. Moreover, yellow, green, and blue light increased protein content, while red and yellow light promoted carbohydrate accumulation. The results suggested that light wavelengths, such as different light colors are important for optimizing biomass yield and biochemical composition. Thus, the knowledge gained provides an advantage for large-scale microalgae production, particularly for high-value bioactive compounds.