Production of ${\gamma}$-Linolenic Acid by Mortierella isabellina IFO 8183

Mortierella isabellina IFO 8183에 의한 ${\gamma}$-Linolenic Acid 생산

To produce ${\gamma}-linolenic$ acid by a mold, cultural conditions of Mortierella isabellina IFO 8183 were investigated. It was found that the increase of initial pH resulted in the decrease of the ${\gamma}-Linolenic$ acid content and the increase of the C/N ratio of medium resulted in the increase of the lipid content. Addition of sodium acetate into the medium resulted in the increased of cell yield, lipid yield, ${\gamma}-Linolenic$ acid content and ${\gamma}-Linolenic$ acid productivity. Under the optimum coditions(glucose, $NH_4NO_3$, C/N ratio of 40, pH 6.0, $30^{\circ}C$ and 0.5% of sodium acetate), the following results were obtained: cell yield, 0.347(g dry biomass/g glucose; lipid yield, 0.18(g lipid/g glucose); lipid content, 0.52(g lipid/g dry biomass); ${\gamma}-linolenic$ acid content, 60(mg ${\gamma}-linolenic$ acid/g lipid); maximum ${\gamma}-linolenic$ acid concentration, 347mg/l after incubation of 8 days.

Mortierella isabellina IFO 8183을 이용하여 ${\gamma}-linolenic$ acid를 생산하기 위한 최적 배양조건을 검토한 결과, 최적 탄소원과 최적 질소원은 각각 glucose와 $NH_4NO_3$이었으며, 지질 생산배지내의 최적 C/N율은 40이었다. 또한, 최적 초기 pH와 배양온도는 각각 6.0과 $30^{\circ}C$이었으며, 균체내에 축적된 지질의 지방산 조성은 pH와 온도에 의해 변화되었다. Sodium acetate를 배양 초기에 0.5%(w/v) 첨가하였을 때 대조구에 비해 ${\gamma}-linolenic$ acid 함량과 ${\gamma}-linolenic$ acid 생성량이 각각 15.4%와 37.8% 증가되었다. 최적 조건하에서 8일간 진탕배양하였을 때 균체수율, 지질수율, 지질함량, ${\gamma}-linolenic$ 함량 및 ${\gamma}-linolenic$생성량은 각각 0.347g/g, 0.18g/g, 0.52g/g, 60mg/g 및 347mg/l이었다.