Multilevel heuristic LED regime for stimulating lipid and bioproducts biosynthesis in Haematococcus pluvialis under mixotrophic conditions.

Enhanced biosynthesis and overproduction of lipid and high-value bioproducts endows microalgae as a promising feedstock for the cost-effective development of advanced bioenergy currently. In this study, multilevel heuristic LED regimes, designed with the coordination of light, nitrogen and carbons in terms of cell physiology and morphology, have been implemented to significantly induce the growth and bioproducts accumulation of Haematococcus pluvialis under mixotrophic conditions. The white-red regime with C5 organic carbon showed a good potential for enhancing microalgal biomass and lipid synthesis, especially for saturated fatty acids. The astaxanthin biosynthesis has been significantly enhanced and the highest content of 3.3% was achieved with gluconate at the white-blue regime. Additionally, white-blue regime enhanced the protein content of H. pluvialis up to 45%, increased by 40% over the white-red culture. The multilevel LED protocol can be developed synergistically with the different adaptation and tolerance of algal cell physiology and morphology for target bioproducts.