Research On Microbial Lipid And Its Preparation Technology

The microbial lipid is also called the single cell oil (SCO) which exists in the cell,synthesized by using the hydrocarbon, the ordinary lipid as the carbon source and inorganicsalt in microbial fermentation process. The microbial lipid mainly includes many kinds ofunsaturated fatty acid, such as triglyeride γ-linolenic acid, arachidonic acid, etc.This paper aims to study Trichosporon fermentans cell disruption methods and the lipidextraction methods and the biosysthetic mechanism of lipid, and compare the ability ofproducing lipid. The research focuses on the possibility and adjustment factors of microbiallipid fermentation by the restaurant wastewater. The results are as follows:1. Trichosporon fermentans were disrupted by freeze-melt method, ultrasonic wavemethod, acid-heating method and freeze-melt&acid-heating method, respectively. The lipidextraction rates of Trichosporon ferments by the ether-benzine and chloroform-methanol werecompared. The results implied that the cells were disrupted by acid-heating and then extractedby the ether-benzine, the lipid extraction rate could reach higher level as high as29.8%.2. The activity of lipase and the accumulation of lipid of Geotrichum robustum，Endomycopsis burtonii，Trichosporon fermentans were studied by shaken flask fermentation.The lipid were extracted after cell disruption by acid-heating, tested the extracellular andintracellular lipase activity, and analyzed microbial lipid components through gaschromatography. The result demonstrated that the ability of accumulation of lipid byTrichosporon fermentans was the strongest and the intracellular lipase activity was up to297U/mL. This displayed that high activity of intracellular lipase contributed to the significantaccumulation of lipid.3. Trichosporon fermentans was cultivated to produce lipid with glucose as the carbonsource and ammonium sulphate as nitrogen source,1%(V/V) soya bean oil as the inducer,0.5%(V/V) Tween-80as emulsifier, at initial pH6.0and30℃for72h, under which cellbiomass, lipid content reached4.72g/L,26.8%, respectively.