Studies On Lipid Production By The Aureobasidium Pullulans P10

In recent years, with the rapid economic development, energy crisis has becomemore and more serious. Developing renewable energy is imperative. Biodiesel isrenewable, safe, non-toxic, and can be used as alternatives for fossil fuels. The lipidcompositions of single cell oil are similar to that of traditional vegetable oils. Moreand more researchers have attempted to use single cell oil as alternatives for biodieselproduction. Traditionally, microorganisms which can accumulate lipids to more than20percent of their dry weight are considered as oleaginous microorganisms. Ingeneral, oleaginous yeasts, which grow much faster and accumulate much more lipidsthan other oleaginous microorganisms, have received increasing attention.After isolation and purification of the yeast strains from the samples of themangrove ecosystems, a total of100yeast strains were obtained. The yeast strain P10which was identified to be a member of Aureobasidium pullulans var. melanogenumwas found to contain the highest oil content in its cells among the100yeast strains.The optimization of the medium for single cell oil production by strain P10werestudied using “one-variable-at-a-time” method. The result showed that the optimalmedium for single cell oil by strain P10were8.0glucose，0.02yeast extract，0.02(NH4)2SO4，0.15MgSO4·7H2O，0.7KH2PO4，0.25Na2HPO4，0.015CaCl2，0.015FeCl3·6H2O，0.002ZnSO4·7H2O，0.002MnSO4·H2O within100ml distilled water. Itwas also indicated that the optimal pH and temperature for lipid accumulation of theyeast strain were6.0and28℃. During10-l fermentation, a titer was66.3g oil per100g of cell dry weight, cell mass was1.3g per100ml, a yield was0.11g of oil perg of consumed sugar and a productivity was0.0009g of oil per g of consumed sugarper h within120h.The compositions of the fatty acids produced were C16:0(26.7%), C16:1(1.7%),C18:0(6.1%), C18:1(44.5%), and C18:2(21.0%). Over90%of the fatty acid from thestrain P10was C16:0, C18:1and C18:2suggesting that the fatty acids could be used as feedstock for biodiesel production. The lipids obtained from the cells of the yeaststrain P10grown in the oil production medium were transformed into biodiesel. It wasfound that over73.7%of the lipids could be transformed into biodiesel within20min.The biodiesel produced from the extracted lipid could be burnt well.