The Breeding Of A Strain Of Lachnum Sp. And Separation And Antioxidant Activity Of Lipid From Lachnum Z60-2

In this paper, a high lipid producting strain of Lachnum sp.(Lachnum Z60-2) wasobtained by the breeding. Fermentation conditions, component and biological activities ofextracellular lipids of Lachnum Z60-2, and purification of methyl linoleate were studied.The main results were as follows:1. Lachnum Z12was induced by N+ion implantation, and Lachnum Z60-2wasacquired through interview screening and senior sereening. The extracellular lipidsproduction (LELZ60) reached to2.02g/L.2. The optimized fermentation conditions of Lachnum Z60-2was glucose13.9%, yeastextract and (NH4)2SO4(1:1)0.4%, MgSO40.07%, pH6. Fed-batch fermentation wasperformed and the production of LELZ60reached to3.7g/L.3. The extracellular lipids (LELZ60) of Lachnum Z60-2content was saturated methylesters (24.1%) and polyunsaturated fatty acids methyl esters (71.4%). The polyunsaturatedfatty acids methyl esters was increased by25.4%than the extracellular lipids (LELZ) ofZ12.4. A positive correlation had been revealed between the concentration of LELZ60(0-60mg/mL) and reducing power. When the concentration of LELZ60was60mg/mL, its OH, DPPH radical scavenging activity and chelating effect on ferrous ions reached thehighest at94.32%,64.81%and82.7%respectively. These results indicated that LELZ60had a strong antioxidant activity.5. The0.05%total favonoids of ginkgo biloba leaves was mixed with lipids (LELZ60)and the mixture was incubated9.2d at70℃. After that the POV was reached16meq/kg, andthe restrain function of lipid oxidation reached the highest at75.2%. The shelf life of lipidat20℃was extended to294.4d.6. The linoleic acid methy was purified by urea inclusion and the optimizedoperational path was LELZ603.0g, urea6.6g, methnol16.5mL,-5℃inclus18h. In thisconditions, the purity of linoleic acid methy reached to50.1%. The lipid was furtherpurified by AgNO3-TLC, and linoleic acid methy was up to96.7%purity.