| Summary: | 碩士 === 國立臺灣大學 === 化學工程學研究所 === 88 === Bacillus subtilis alpha-amylase (EC 3.2.1.1) losses over 80% activity at low concentrations in deionized water. This study mainly investigated the stability enhancement of alpha-amylase caused by supercritical carbon dioxide (SC-CO2) pretreatment. The alpha-amylase powder is pretreated for 1 hour in SC-CO2 at certain pressure and temperature. Moreover, the denaturation of pretreated lysozyme (EC 3.2.1.17) was also evaluated to examine the effect of the SC-CO2 pretreatment.
Experimental results indicated that the stability enhancement was observed when the SC-CO2 conditions are set to 50℃ with 2000 or 2500psi and 60℃, 3000psi. The optimal SC-CO2 condition for the alpha-amylase is found to be 60℃, 3000psi and the pretreated alpha-amylase maintained the 33% activity compared the original one only 20%. Besides, the 60℃-3000psi- (SC-CO2) pretreated alpha-amylase increased 2 times in the solution stability.
The results also showed that SC-CO2 pretreatment also applied to stabilize lysozyme (EC 3.2.1.17). Compared with the original lysozyme lost 60~75% activity in an hour when denatured by urea, the lysozyme pretreated by 40℃, 2500psi SC-CO2 maintained 60~80% activity after 2 hour. The result means that the stability enhancement by SC-CO2 is not specific to -amylase and other enzyme can also adapt to this method.
The results of the experiment provide a novel method to improve the enzymatic stability.
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