Effect of temperature and light spectrum on the Lutein and Beta-carotenoids production in Chlorella vulgaris algae

Algae contain carotenoids as granules that give them red, orange, or yellow hues. B-carotene acts as an antioxidant, protecting the body from free radicals, enhancing the immune system, and contributing to cell growth and differentiation. Lutein is a carotenoid found in plants and phototrophic microorganisms. Lutein is widely used as a nutraceutical for human health. This study aimed to investigate the impact of temperature (20, 25, and 30°C) and the light spectrum (red, blue, and white) on the production of lutein and ?-carotene in Chlorella vulgaris. A special incubator cabin was designed for the study, containing three sections: the first part, corresponding to the red spectrum, had an illumination intensity of 152 µmol/m²/s; the blue spectrum had an illumination intensity of 1194 µmol/m²/s; and the white spectrum had an illumination intensity of 303 µmol/m²/s. Four replicates were prepared for each treatment, and two samples were drawn for lutein and ?-carotene pigments on the 9th and 18th days. The results showed that the lutein concentrations ranged between 0.001-5.27 µg/ml at 25°C in the white and blue spectrums, respectively, while the highest concentrations of lutein were at 25°C in the blue spectrum on the 9th day. The results also indicated that the highest concentration of ?-carotene at 20°C was 9.2 µg/ml in the blue spectrum on the 18th day. The study concluded that the best concentrations of lutein production were at 25°C in the blue spectrum on the 9th day, while the best concentrations of ?-carotene production were at 20°C in the blue spectrum on the 18th day of the experiment.