Studies On Fermentation And Extracting Technics Of γ -Linolenic Acid Lipid

Gamma linolenic acid (GLA),mainly obtained from natural plants ,has a very important physiological function.But the production can not suffice the market demand. GLA production by microorganism fermentation is becoming more and more popular. By studying the effect of different factors on the production of GLA through filamentous fungi (Cunninghamella echinulata) fermentation, the metabolic rules in potato media and the optimal fermentation conditions were obtained. The correlative factors in fermentation were studied by experiments. The results indicated that the second fermentation in PDY medium with 10% incubating volume is the optimal flask fermentation. When the medium is prepared,organic and inorganic nitrogen sources should be added to improve the activity and the quality of germ. Appropriate organic nitrogen source is a necessary component of fermentation medium.At the end of fungus growth,adding proper carbon source can elongate the anabolic circle of production and obtain more lipid full of GLA. Studies on the optimal material complementarity technics indicate that when the fungus cultivated in the fermenting culture medium cotaining 0.25% soybean powder after cultivated 10 days,the yield of biomass, total lipid ,GLA% and the absolute content of GLA were 17.065g/L, 6.530g/L,23.5157% and 1535.58mg/L, respectively were increased 79.67%,217.30%,14.85% and 264.43% correspondingly by supplying nutrient substance in batches.During the process of incubating ,2%carbon source was added in the fermentation system at the end of the second day and 3% carbon source and (NH4)2SO4 (1.0g/L) were added in the same system at the end of the third day.(the carbon source were composed of edible sugar 20g/L and maltose 10g/L ).And MgSO4(2.0g/L) and MnSO4(2.0g/L ) were added separately on the fifth and sixth day. The disposal technics was also studied. The results indicated that high-temperature baking in short time with the fragmenting the cell through mechanical technique can shorten the processing time and eliminate the activity of fungus,but have little effect on the production of GLA.What,s more, the color and odor of the obtained lipid are good.The technics shows a promising prospect in industrialization. The optimal conditions of producing abundant lipid with high contents of GLA was obtained.It is time-spared and high efficient.This paper provids some reference in the production of GLA in industry.