Thermal stabilization of lipase by sol-gel entrapment in organically modified silicates formed on kieselguhr
Thermal stabilization of lipase by sol-gel entrapment in organically modified silicates formed on kieselguhr
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DOI：
10.1016/0922-338x(96)88814-3
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发表时间：
1996-01-01
期刊：
影响因子：
--
通讯作者：
Yoshida, S
中科院分区：
文献类型：
--
作者：
Kawakami, K;Yoshida, S
研究了溶胶-凝胶法包埋有机改性硅酸盐的脂肪酶在有机溶剂合成酯中的催化活性和热稳定性。以甲基三甲氧基硅烷（MTrMOS）为有机硅烷前驱体，与四甲基氧基硅烷（TMOS）以3:1的摩尔比混合，在65℃的温度下，包裹的脂肪酶比沉积在Celite 545上的脂肪酶表现出更高的酯化活性，这种酯化活性通过在Celite 545表面形成脂肪包裹凝胶进一步增强。杂化凝胶包埋对脂肪酶的热稳定作用似乎与伴随微观相分离的溶胶-凝胶转变机制密切相关。通过对不同有机硅烷的筛选和制备条件的优化，发现在Celite 545上由丙基三甲氧基硅烷或三甲氧基硅烷与TMOS等摩尔混合物制备的杂化凝胶包覆的脂肪酶最耐热，在75℃下保持其全部活性，在95℃下的活性比在相同载体上沉积的脂肪酶高100 ~ 200倍。
The catalytic activity and thermal stability of lipase entrapped in organically modified silicates by the sol-gel method have been studied in ester synthesis in organic solvents. When methyltrimethoxysilane (MTrMOS) was used as the organic silane precursor which was mixed with tetramethoxysilane (TMOS) at a molar ratio of 3 : 1, the entrapped Lipase exhibited a higher esterification activity than the lipase deposited on Celite 545 at temperatures as high as 65 degrees C. This esterification activity was further enhanced by forming the lipase-entrapping gel on the surface of Celite 545. Thermal stabilization of lipase by entrapment in hybrid gels seems to be closely related to the mechanism of the sol-gel transition accompanied by microscopic phase separation. As a result of screening of different organic silanes, and of optimization of the preparation conditions, the hybrid gel-entrapped lipases on Celite 545 derived from an equimolar mixture of either propyltrimethoxysilane or trimethylmethoxysilane and TMOS were found to be the most thermostable, retaining their full activities up to 75 degrees C, and 100 to 200 times higher activity at 95 degrees C compared to the lipase deposited on the same support.