Abstract
Docosahexaenoic acid (DHA) has recently attracted nutritional attentions through its specific function in brain/retina as well as beneficial effects of (n-3) polyunsaturated fatty acids. Firstly, the physiological activity of DHA is reviewed from recent publications, and compared to the activity of icosapentaenoic acid (IPA), with respect to its incorporation into plasma/tissues, its anticoagulant/anti-inflammatory effect, its effect on brain/retina, its anticancer effect, and adverse effects of excess intake, if any.
Secondly, reports on microbial lipid (single cell oil, SCO) production including DHA are reviewed, which include Crythecodinium cohnii, Thraustochytrium aureum, Vibrio marinus etc. Two trials for DHA-SCO using C. cohnii has revealed high cell/DHA productivities in a semicontinuous culture (50 g/L of cell mass) and a continuous culture (120 mg/L·h of DHA). A new strain, SR 21, isolated from the coral sea water in Yap Islands and identified as Thraustochytrium sp., showed tolerance to high concentration of glucose and to mechanical mixing and resulted in the highest DHA productivity at 4000 mg/L in a fermenter culture for 7 day.
