Blue light-enhanced Desmodesmus sp. biomass yield in requirement opposite for high yields of macronutrient starvation-based lipid or nutritional excess-based pigment using red light

The present work has aimed to optimize the amounts of lipids , carotenoids , and chlorophylls yielded by microalga Desmodesmus sp. in photobioreactors , performing suitable changes in nutritional and colored light source conditions. The enhancement of byproduct yields was also addressed, based on white and colored lights. 16-day algal growth kinetic tests were performed, testing white, blue, red, and green lights. Based on the Response Surface Methodology (RSM), a 3 2 -factorial design was applied, combining suitable changes in concentration factors of both primary nutrients K 2 HPO 4 and NaNO 3 . A significant improvement in the production of carotenoids , chlorophylls, and lipids in a red-light-based illuminance was observed. Finally, increasing the amounts of K 2 HPO 4 and NaNO 3 in a red light environment allowed the attainment of the highest yields of carotenoids and chlorophylls, in contrast with a high yield of lipids due to applying nutritional stress with an amount decrease of K 2 HPO 4 and NaNO 3 . • Improvement in the growing of Desmodesmus sp. using optimized nutritional conditions. • Optimized wavelength range and K 2 HPO 4 and NaNO 3 amounts improved byproduct yield. • Red light wavelengths enhanced the yield of carotenoids , chlorophylls and lipids. • Increasing K 2 HPO 4 and NaNO 3 using red light allowed better carotenoids and chlorophyll yields. • A depletion in K 2 HPO 4 and NaNO 3 amounts using red light improved lipid yields.