Studies on the production of arachidonic acid by fungal strains of mortierella sp.

• Main Authors: Fang, Wen Feng, 方文鋒
• Other Authors: Su, Yuan Zhi
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/47356010034122095612

碩士 === 國立臺灣大學 === 農業化學研究所 === 83 === Various soil samples were collected and cultivated at 10℃ for isolation and screening of high arachidonic acid (ARA)producing microorganisms, and 15 strains showed preferable productivities. Among these microorganisms, two isolated fungi,strains F4 and F12 have the best yield of 1256 mg/L and 1023 mg/L, while cultivated in HD medium at 25 ℃, 125 rpm for 6 days,respectively. Strain F4 was identified and named as Mortierella alpina NTU-F4. In order to produce most highest amount of ARA with these two strains, the cultural conditions were investigated. The optimal medium compositions for production of ARA by strains F4and F12 in fermentor were: 8% glucose, 1% yeast extract, 0.48% KH2PO4, 0.2% KNO3, 0.02% CaCl2 ． 2H2O, 0.1% MgSO4 ． 7H2O,0.003% FeCl3． 6H2O, 0.0015% ZnSO4 ． 7H2O, 0.0001% CuSO4 ．5H2O, pH 5.5. When F4 strain was incubated in the optimal medium shown above at 25 ℃, 400 rpm, 0.5 vvm in 5 L fermentor for 6 days, the biomass (28.6% g/L) contained 18.1% ARA as 51.7% (w/w) of total fatty acids, intracellular ARA reach 5189 mg/L. When strain F12 was incubated in the optimal medium shown above at 25 ℃, 450 rpm, 0.5 vvm in 2.5 L fermentor for 6 days,the biomass (31.1 g/L) contained 12.0% ARA as 37.5% (w/w) of total fatty acids, intracellular ARA could reach 3743 mg/L. The lipid extraction was investigated and n-hexane shown as the prefer solvent for recovery of ARA. Triacylglycerol (TG) is the main component of the lipid complex, and most ARA exist on it.