Optimization of light conditions by affecting the growth and production of C-Phycocyanin in Spirulina platensis microalgae

Spirulina microalgae are a rich source of protein and valuable biological compounds. One of the most important Spirulina microalgae pigments is phycocyanin. Phycocyanin is widely used in industries as a natural blue pigment and it’s also an effective antioxidant. In order to improve phycocyanin production as well as Spirulina growth, by autotrophic cultivation considering that autotrophic cultivation depends mainly on the source of light with different wavelength distribution and intensity and also access of the Spirulina microalgae to nutrients ingredient in culture medium. Given that phycocyanin is a photosynthetic pigment, and a component of light-harvesting (antenna) complexes, the rate and efficiency of the photosynthetic activity is important in the production of phycocyanin. In this study, the molecular 16srRNA identification of spirulina strains was performed. The best strain (Arthrospira platensis NIES-39) in terms of biomass and phycocyanin production was selected from five spirulina strains. The effect of different super Light Emitting Diode (LED) emitting white, red and blue as a light source in terms of biomass and phycocyanin production in Arthrospira platensis NIES-39 were compared, and the results showed that white super LED had the best performance significantly in terms of biomass production (4.71 g/l) and the highest concentration of phycocyanin (0.316 mg/ml). But the purity of phycocyanin produced by blue super LED (1.04) was significantly higher than white super LED (0.77) and others. The results also showed that the use of combined wavelengths of white and red super LEDs in the growth stages of Arthrospira platensis NIES-39 compared to the use of only each ones increased the growth rate of algae and three-day shortening the growth period to achieve the maximum biomass (4.67 g/l). As a general result, it can be said that the use of super LED could increase the biomass, purity and amount of phycocyanin produced in the economic production of this microalgae.