Astaxanthin Production and Expression of its Metabolic Pathway Genes under the influence of Linoleic Acid and Nanoparticles in Microalga (Hematococcus Lacustris)

Astaxanthin is a precious material and has many favorites for human; it is extracted from some creatures such as Haematococcus lacustris. Researchers try to maximize the production of this material. In this research effects of linoleic acid (LA), TiO2 and SiO2 Nanoparticles (NPs) were investigated on astaxanthin production, and expression of two astaxanthin metabolic pathway genes (CRTO and CRTR). The microalgae was cultured in BBM medium for 19 days autographically. In 3rd day, treatments were added to the cultures and astaxanthin measured in 3 days respectively in logarithmic and stationary phases, also RNA was extracted, Real-time PCR applied and Gene expression investigated in 11th. 30 µM LA and TiO2 NPs (40 mg L-1) induced 3.4 and 1.5 times astaxanthin production compared to the control, furthermore, CRTO and CRTR under 30 µM LA and SiO2 NPs (40 mg L-1) treatments displayed the highest gene expression. It was demonstrated that special concentration of Linoleic acid and TiO2 NPs, as inducers, could be used for astaxanthin production; also, Linoleic acid has a direct relationship with astaxanthin production and CRTO´s gene expression in the microalgae.