Abstract: To get high content of docosahexaenoic acid (DHA,ω-3), the effects on the Cephalosporium sp. mycelium’s fattyacid composition of strain storing and culturing conditions were studied. The strgins containing microorangism were stored at 20℃、4℃and-20℃ for different times respectively. The fatty acids were analyzed by GC. The results showed that the fatty acidcomposition was affected by the storing temperature、storing time no matter how the strain was activated on new agar beforefermentation. If the strain was cultured on new agar before fermentation, the 10d period was the best storing time to get highsDHA content. If not cultured, to the 20℃, the best time was 20d; to the 4℃, the best time was 25d and to -20℃, it was 5d. Thepolyunsaturated fatty acid (PUFA) changed the same tendency as the DHA’s but at 4℃ not so. At 20℃, the index ofunsaturated fatty acid (IUFA) and the 18:3 (α-)/18:2 changed with the same tendency as the DHA’s. Storing the strain at -20℃, the PUFA、IUFA and DHA fluctuated at the lowest range. This study could give a theoretical reference for producing highyield of DHA by microorganisms.

Key words: Cephalosporium sp., strains storing and culturing, docosahexaenoic acid (DHA), fatty acid composition, polyunsaturatedfatty acid (PUFA)