Fatty acids, sterols and α-tocopherol in Isochrysis galbana

The production of fatty acids, sterols and a-tocopherol by Isochrysis galbana. under 24 h and 8 h lighting was studied. The most abundant fatty acids were 14:0, 16:0, 16:1, 18:40, 20:5omega3 and 22:6omega3. Higher accumulation of monounsaturated fatty acids was observed in the decay phase whereas in the lag phase polyunsaturated fatty acids (PUFA) were the major group. The shorter light period seemed to increase the production of PUFA. Sitosterol and stigmasterol were the two main sterols detected achieving the levels 246.3 and 220.0 mg/100 g, respectively. A continuous increase in the level of total sterols was recorded during the life cycle at 24 h lighting. The reduction of the photoperiod led to a decrease in the total sterols produced in the decay phase. An increase in a-tocopherol production during the life cycle was recorded. The reduction of the lighting period considerably decreased the biosynthesis of this antioxidant.