Obtaining high purity eicosapentaenoic acid from the microalgae Phaeodactylum tricornutum using a three stage process

摘要

Eicosapentaenoic acid (EPA), which is of great benefit to human health, was obtained from the microalga Phaeodactylum tricornutum using a three stage process: extraction of the fatty acids by direct saponification of the moist biomass, concentration of the polyunsaturated fatty acids (PUFAs) by the urea method and purifying the EPA by high resolution liquid chromatography (HPLC). The fatty acids were extracted using KOH-ethanol (96% v/v) (1 hour, 60 degree C) extracting 90.9% of the EPA present in the biomass. The urea/fatty acids ratio was 4:1 w/w, the crystallization temperature 28 degree C and methanol was used as solvent for the urea, providing a yield of 78.6% of EPA. EPA was purified on a 4.7 cm i.d. x 30 cm column, C18 inverse phase using methanol-water (1% HAc) 80:20 w/w as the mobile phase; 97.3% of the EPA placed in the column was recovered with a purity of 95.8%. The overall yield of the process is 69.5%. The output of high purity EPA is 2.46 g/day, determined by the output of the biomass of Phaeodactylum tricornutum in an outdoor tubular photobioreactor (100g/day). The same process can be applied to other microalgae and to obtain other PUFAs.