Effects Of Irradiation Domestication And Drying Methods On The Synthesis Of Cyclopentadecanolid

Cyclopentadecanolide is an important macro cycle musk, which not only hasdelicate odor of musk, but also can make the perfume compound elegant and gentle.It is widely used in many fields, such as perfume,cosmetic, food,and medical etc. Atpresent, the synthesis of this product by biocatalyst has been popular in the spicefield throughout the world.Since 15-Hydroxy-pentadecanoic acids are used as substrate to the synthesis ofmacro cyclic lactones by lipase is discovered, the study on catalysis of macro cycliclactones by lipase has been popular throughout the world.Lipase from microbe is used as a catalyst to synthesize cyclopentadecanolide.And the substrate is 15-hydroxy pentadecanoic acid methyl ester. It mainlyconcludes three aspects: (1) discussing the conditions whose strains byUV-irradiation has produced lipase; (2) effects of drying methods on lipase activityand catalytic properties; (3) study on temperature domestication of lipase. The mainresearch conclusions are as follows:1.Lipase activity produce by Candida spGXU08 strains by UV-irradiationfermented reache 24.SU/mL. Lipase activity increase by over 33.2% contrasting withthe original strain. The effect of pH and temperature on activity and stability oflipase and the effect of time and temperature on lipase production are discussed.2.Lipase is dried by different drying methods, such as freeze-drying,vacuum-drying, and N₂ drying. The results showed that the effect of freeze-drying isbetter than vacuum-drying. And N₂ drying is the worst; the raw enzyme powder isnot completely dried. It retains 63.9% of the enzyme activity after drying. It.is worsethan 78.74% by freeze-drying and 75% by vacuum-drying. The conversion ofsubstrate catalyzed by lipase and dried by vacuum-drying is 2.06%. The conversionby freeze-drying is 2.21%. The difference between them is not great. However, theconversion by N₂ drying is only 0.95%.3.Temperature domestication of lipase is investigated. The results indicatethat repeating 7 fermentations, with fermentative temperatureincreasing by degrees, tolerability of seed broth and fermented broth to temperature are improved. Fermented broths that is added seed broth with temperatureprogramming ferment with temperature programming, that is added seed broth withtemperature programming to ferment at same temperature, and that is added seedbroth at same temperature to ferment at same temperature, are respectively dried toprepare enzyme powder. The conversion of substrate are respectively 2.51%, 2.32%, 2.04% under the same lipase activity.