Development of a Temperature Shift Strategy for Efficient Docosahexaenoic Acid Production by a Marine Fungoid Protist, <Emphasis Type="Italic">Schizochytrium</Emphasis> sp. HX-308

Temperature was one of the important environmental factors affecting the biosynthesis of docosahexaenoic acid (DHA; C22:6, ω−3). Generally, a low temperature would slow the strain growth, but promote the accumulation of unsaturated fatty acids. According to this information, the effects of temperature and different two-stage temperature shifting strategies on fatty acid production and DHA content of the marine fungoid protist, Schizochytrium sp. HX-308, were investigated in this study. Finally, the highest DHA percentage was up to 51.98% (per total fatty acids) with the DHA production of 6.05% (per dry cell weight), which was obtained with the method of shifting temperature from 30 °C for 32 h to 20 °C for 12 h.