Microalgal Lipid and Its Application

Abstract

Docosahexaenoic acid (DHA) and icosapentaenoic acid (EPA) are valuable nutrients because they have important roles as the constituents of structural lipids in the nervous tissues of human brain and retina. In addition, DHA, EPA and other omega-3 fatty acids are important factors in the prevention of several human diseases. Fishes have been the dietary source of these fatty acids and they originate from the marine microbes upon which the fishes feed. Therefore, these marine microbes cultured under control could be utilized as alternative source of the omega-3 fatty acids.Marine microalgae are rich in DHA and EPA. However, very few species of freshwater algae contain significant amounts of these compounds. The marine unicellular alga Isochrysis galbana is well known as a source of such fatty acids and this species has been used extensively as a food source for aquaculture. The advantage of the marine microalgae such as I. galbana over other microbes as sources of polyunsaturated fatty acid is that this alga may be grown photosynthetically using carbon dioxide as the sole carbon source and seawater as a source of minerals.In this paper, we focused on the production of marine microalgae as an alternative source of polyunsaturated fatty acid. We have screened a number of species of marine microalga specifically for their ability to produce DHA and EPA and have optimized the growth conditions for I. galbana. The utilization of microalgae as feed for cultivation of rotifers is also reported. Moreover, the applications of genetic engineering for EPA production are also demonstrated.