Comparison Of Fermentation And Characterization Bewteen The Lipase And Protease Of Trichosporon Fermentans

The partial cultural condition and characterization of the lipase of Trichosporon fermentans were studied. The effect of its protease on the synthesis of lipase was investigated. The conclusions were as follows.The lipase from Trichosporon fermentans was intracellular enzyme. The cell disruption and lipase release by ultrasonication was examined. The lipase activity reached128.46U/g under the optimal extracting condition: output power550W, duration of irradiation each time6s (with a5s interval), total irradiation time5.5min, the cell concentration25g/L. The permeability of Trichosporon fermentans cell was improved by treating cells with ultrasonication. The intracellular lipase activity after permeabilization was enhanced under the optimal treating condition: output power180W, duration of irradiation each time2s (with a5s interval), total irradiation time1.2min, the cell concentration40g/L.The optimal concentration of glucose in inoculum medium for the lipase and protease fermentation was80g/L. The protease was found to reach the hightest activity308.8U/g at60h culture, whereas the hightest activity of lipase was96U/g at72h culture.The optimal catalytic condition of crude lipase and protease in the liquid extracted by ultrasonication were55℃, pH6.8and pH7.0, respectively. Both crude enzymes were stable with the rage of pH5.0-6.0and20-40℃. The lipase and protease at-20℃remained80%and100%activity for3days, respectively. The cations Mg2+, Zn2+, Cu2+, Ca2+, Mn2+reduced the activity of lipase, and Ca2+, Mn2+partially stimulated protease. N-hexane stimulated the lipase, while fully inhibited the protease. Both crude enzymes could be activated by0.01%(v/v) Triton-100, and the activity of lipase and protease were increased by112.19%and23.03%, respectively. Both crude enzymes were totally stimulated by7.5%(w/v) sucrose. It was revealed that1-2.5%(w/v) casein and7.5%(w/v) amylodextrine were better protectant for lipase but not for protease.