1United Graduate School of Agriculture, Kagoshima University, Kagoshima 890-0056, 2Department of Biological Production and Environmental Science, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, 3CycloChem Co., Ltd., Kobe, Hyogo 650-0047, 4Bizen Chemical Co. ltd., Kumayama, Okayama 709-0716, Japan
Nutritional fortification of Spirulina with docosahexaenoic acid (DHA) was attempted. Fish oil, DHA-ethyl and free DHA were supplemented into the culture of Spirulina as a source of DHA. Exogenous DHA in triglycerides and ethyl ester were not taken up into Spirulina cells. However, the cells took up the DHA in free form from the culture media. The cells without supplementation with DHA did not contain DHA in the cellular fatty acids. The DHA content of the cells was greatly increased by supplementation with DHA into the culture media. It reached to 70.2% of the total fatty acid in the cells.
DHA was mainly incorporated into the neutral lipids such as monoglycerides and diglycerides in the cells. Free fatty acids were slightly detected in the DHA-fortified cells. A small amount of DHA was also incorporated into glycolipid and phospholipid fractions. Sulfoquinovosyldiacylglycerol in the DHA-fortified Spirulina contained 9.1% of DHA in the total fatty acid. However, only 1-2% of DHA were incorporated into the other polar lipids.