超临界CO2中脂肪酶催化反应的研究 |
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引用本文: | 图,压力对酶初始反应速率的影响.超临界CO2中脂肪酶催化反应的研究[J].清华大学学报(自然科学版),1999,39(6):31. |
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作者姓名: | 图 压力对酶初始反应速率的影响 |
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作者单位: | :清华大学 化学工程系,北京 100084 |
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摘 要: | This paper studies the lipase-catalyzed
esterification of lauric acid and n-butanol in supercritical carbon dioxide.The method
is the same as described in “Journal of Tsinghua University” (Qinghua Daxeu Xuebao),vol.39,No.6,pp31~34,1999,by
CHEN Huiqing,YANG Jichu.The effect of pressure,temperature,water content of the
enzyme,concentration and type of the substrates on the reaction are evaluated.Increasing
the pressure will make the hydration extend of the enzyme decrease,along with the
decrease of the activity.However,the solubility of all substrates increase when
turning the pressure from 8MPa to 20MPa,a higher reaction rate thus is induced.In the
range of 34℃~60℃,increase of the temperature will cause a tendency of higher
reaction rate.The water contents of the enzyme have a great impact on the reaction.The
activity of the enzyme reaches its peak at the water mass fraction of 40%.If the
concentration of n-butanol is greater than 100mmol/L,an obivous inhibition on the enzyme
is observed.During each experiment,lauric acid did not inhibit the reaction.The
initial rate increases with the extending of carbon chain in alcohol molecule.When the
number of carbon atom is more than 4,the reaction rate lowers down.
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关 键 词: | 超临界二氧化碳 酶催化反应 月桂酸 酯化 |
修稿时间: | 1998-07-08 |
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