Polyunsaturated Fatty Acid Production with Mortierella alpine by Solid Substrate Fermentation

Abstract

Polyunsaturated fatty acids (PUFA) were produced with Mortierella alpina by solid substrate fermentation. Rice bran was the most effective substrate for PUFA production, followed by peanut meal residue, wheat bran, and sweet potato residue. The optimal conditions for PUFA production were rice bran supplemented with 2.3 to 5% nitrogen at an initial moisture content of 65 to 68% and a pH range of 6 to 7. Each gram of substrate carbon yielded 122.2 mg of total PUFA, including 12.8 mg of eicosapentaenoic acid (EPA), 47.8 mg of linoleic acid (LA), 7.1 mg of a-linolenic acid (ALA), and 54.5 mg of arachidonic acid (ARA) for 8 to 12 days incubation. C/N ratios between 14.5 and 18.5 favored EPA and LA production, while C/N ratios between 19.8 and 21 enhanced ARA and total PUFA production. Total PUFA, EPA and ARA production increased 12, 84.4 and 46.1%, respectively, when the culture temperature was shifted from 20℃ to 12℃ on the fifth day. Supplement of soybean and linseed oils increased LA by 84.9 and 36%, ARA by 71 and 42.1%, and EPA by 130.6 and 92.1%, respectively.