Production of eicosapentaenoic acid by the marine eustigmatophyte Nannochloropsis
Very long chain polyunsaturated fatty acids (VLC-PUFA) that belong to the omega3 group, are essential fatty acids for the development of marine organisms and important in a balanced human diet. Medical studies showed that these fatty acids in the human diet may reduce morbidity risks of coronary heart diseases (Simopoulos, 1986). Recent studies indicated that omega-3 VLC-PUEA, mainly docosahexaenoic acids (DHA), are essential for the development of the brain, the retina and the nervous system in human (Innis, 1992). DHA is an important fatty acid found in human breast milk, but is lacking in commercially available infant formulas (Kyle et al., 1992). The current major source for omega-3 VLC-PUFA is fish oil that contains both eicosapentaenoic acid (EPA) and DNA. Although fish oil is an abundant source of both EPA and DHA, there are some significant problems associated with the use of fish oil as a food supplement (Boswell et al., 1992). Unicellular algae that synthesize EPA and DHA would be a useful source for these essential fatty acids. Microalgae are a large and diverse group of photosynthetic microorganisms. Microalgae are known as the primary producers and the foundation of essential fatty acids in the food web of marine life. The cultivation of microalgae for EPA production has been developed and is mainly applied in the aquaculture industry, although attempts were made to use this source of essential fatty acids as human diet supplements and animal feed.