The Mortierella Unsaturated Acid Gla High-yield Strains Of Research

In this article, strain screening, selection of primary screening methods, optimization of fat-producing conditions and enriching of polyunsaturated fatty acids were studied.Mortierella ramanniana is a fungi of producing poly-unsaturated fatty acid.lt was noticed and applied widely because of various action of its poly-unsaturated fatty acid in producing medicament, nutriment, health products and feedstuff et al.In deficiency badly of resource of animals and plants,it take on great development potentiality by producing effectively poly-unsaturated fatty acid.But at present,the needful output of the Mortierella is not quantum sufficient and the cost of production is too expen- sive.So It is necessary to lure and change seed selection to this fungus, screen its output of oil, especially γ-linolenic acid strain high in output.In the article,when we mutant the Mortierella ramanniana, compound to mutant to the fungi with the nicotine and ultraviolet ray at first;and obtain -ed IM_F2. its fungus body output, the content of lipid and the content of GLA are higher about 34.38%, 6.9% and 20.83% than the original strain M5;Then, DNA transform through into the spore,and obtained M_F2-70, its fungus body output, the content of lipid and the content of GLA are respectively 42.8 g/L, 32.13%å'Œ 9.4%; finally, passing the preparation of the protoplasts, compound to mutant the protoplasts with HNO2 and laser. A mutation strain of high yield M_F2-70-12 appears in the seed selection from the original strain M_F2-70. This fertile strain is selected by the comprehensive method that the lack carbon and high carbon trains etc, hereditary stability experiment, esterase isoenzyme exam-inement etc. the results show that M_F2-70-12 is a mutation strain of stable, variant, heavy producing. And it is trained in shaking bottle, and obtained its fungus body output, the content of lipid and the content of GLA are raising respectively to 198.6%, 150.2%, 260.4% by the original strain M5.At the same time, optimizing the cultivation condition of this fertile strain in influence the production of fungus body and the output of lipid and passing the singlefactor experiment, the results show: culture composition, inoculating amount, temperature, PH etc. have great influence on the fungus body output, the output of lipid and the composition of lipid. As follows: 120% glucose, 5% urea, (NH^SC^ 2 g/L, KH2PO43 g/L, Mg SO4 ? 7H2O 0.5 g/L ,1% citric acid, 0.4g/L yeast cream, 0.3g/Lpeptone,microelement lipid lmL,constant volume to 1000 mL, pH 5-6, temperature 28-30°C inoculab- ility amount 5%-10% .