Effect of phosphorus and nitrogen levels and light emissions diodes illumination on growth and carotenoid synthesis in Jaagichlorella luteoviridis. Optimization of carotenoid extraction

Abstract

Modifying incident irradiance and colour can increase microalgal composition and productivity. The objective of this work was to evaluate the effects of LED light on Heterochlorella luteoviridis, recently renamed as Jaagichlorella luteoviridis, simulating circadian solar radiation. The influence of white, red, and blue light on the growth rate and biomass composition was studied. Prior to this, the optimal N/P ratio and initial nitrate concentration were investigated. Carotenoid extraction was also optimized for this microalga. To achieve complete carotenoid extraction, J. luteoviridis required a temperature of 60 °C and 20 % KOH. Furthermore, an N/P = 5 increased the carotenoid content by 10 % while an initial nitrate concentration of 10.59 mM exceeded the carotenoid productivity of the control by 48 %. An increase in white irradiance led to a higher biomass growth rate and protein content but lower carotenoid and lipid contents. In contrast, an increase in red light resulted in a higher growth rate, while blue light increased the high-value products content.