The Effect of Colors and Light Intensity on the Growth and Biochemical Compounds of the Chlorophyceae <i>Nephroselmis</i> sp.

Light intensity and spectral quality play crucial roles in microalgal growth and biochemical biosynthesis. This study investigates the effects of different light intensities (3000, 8000 and 15,000 lux) and colors (red, white, yellow and green) on the growth and metabolites of <i>Nephroselmis</i> sp. Moderate intensity (8000 lux) of white light is sufficient to produce this microalga. The colors of light strongly affect the parameters of the growth of <i>Nephroselmis</i> under each light intensity (<i>p</i> < 0.05). The yellow and green light supported the highest growth rates for the three intensities. Blue and green light at 15,000 Lux stimulates high levels of chl-<i>a</i> corresponding to antenna size 2.80 and 2.46. <i>Nephroselmis</i> illuminated with red light synthesizes carotenoids reaching 13 µg mL⁻¹ at 15,000 lux. This latter for each color stops the proliferation of <i>Nephroselmis</i>, and cells shift their metabolism towards the accumulation of protein. <i>Nephroselmis</i> accumulates more protein, followed by carbohydrates, lipids and polyphenols. <i>Nephroselmis</i> exhibited the highest protein (64% D.W) content when cultured under white light, and the green at 15,000 lux enhanced their production. <i>Nephroselmis</i> is rich in carbohydrates, which accounted for more than 20% D.W under all combinations of light intensities and colors. The accumulation of polyphenols and carotenoids under high-intensity red and white light may reflect an oxidative stress response, suggesting their role as protective antioxidants. The capacity of <i>Nephroselmis</i> sp. to thrive and synthesize valuable metabolites under variable light regimes underscores its potential as a robust candidate for the production of various molecules.