Water Activity Dependence of Lipases in Non-aqueous Biocatalysis
Water Activity Dependence of Lipases in Non-aqueous Biocatalysis
复制标题
非水生物催化中脂肪酶的水活度依赖性
DOI：
10.1007/s12010-009-8618-8
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发表时间：
2009-05
影响因子：
3
通讯作者：
中科院分区：
文献类型：
--
作者：
对11种脂肪酶进行了测定，发现根据对水分活度的依赖性，脂肪酶可分为3种类型。第一类脂肪酶对水分活度的依赖性较低，在低水分活度下工作，其性能随水分活度的变化不大。最适水分活度为0.19，Newlase F（Rhizopus niveus）、FAP-15（Rhizopus niveus）属于这类酶。第二类是具有中等水分活度依赖性的脂肪酶，其性能随水分活度的变化而变化。大多数脂肪酶属于这一类型，这一类型的最佳水分活度约为0.60。第三种类型是具有高水分活度依赖性并且仅在高水分活度（aw> 0.75）下起作用的脂肪酶。WGL（小麦胚芽）属于这一类型，其最适水分活度为0.90。讨论了水活度与对映体选择性的关系，发现水活度与对映体选择性无关。并对水活度的两种控制方法进行了比较，发现在反应混合物中加入固体水合盐的方法（方法II）比通过气相预平衡的方法（方法I）在整个反应过程中更稳定和有效。对水合盐的加入浓度也进行了研究，最佳加入浓度为1g/l。
Eleven lipases are tested and it was found that lipases can be divided into three types according to water activity dependence. The first type is lipase that has low water activity dependence and works in a low water activity, its performance changes little with the change of water activity. The optimum water activity is 0.19 and Newlase F (Rhizopus niveus), lipase FAP-15 (Rhizopus oryzae) belong to this type. The second type is lipase that has medium water activity dependence and its performance changes with the change of water activity. Most lipases belong to this type and the optimum water activity in this type is about 0.60. The third type is lipase that has a high water activity dependence and works only in a high water activity (aw> 0.75). WGL (wheat germ) belongs to this type and the optimum water activity is 0.90. The relationship between enantioselectivity and water activity is also discussed and the enantioselectivity seems to be independent of water activity. And we also compared the two control methods of water activity, it was found that the method which add solid salt hydrates to the reaction mixture (method II) is more stable and effective throughout the reaction than the method that pre-equilibrate via the vapor phase (method I). The addition concentration of salt hydrates is also investigated and the optimum concentration is 1 g/l.
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影响因子：
5
作者：
R. Perraud;F. Laboret
通讯作者：
R. Perraud;F. Laboret
DOI：
10.1002/9783527618262.ch8
发表时间：
2002
期刊：
--
影响因子：
--
作者：
P. Halling;K. Drauz;H. Waldmann;S. Roberts
通讯作者：
P. Halling;K. Drauz;H. Waldmann;S. Roberts
影响因子：
3.4
作者：
N. Micaêlo;V. Teixeira;A. Baptista;C. M. Soares
通讯作者：
N. Micaêlo;V. Teixeira;A. Baptista;C. M. Soares
影响因子：
--
作者：
P. Halling
通讯作者：
P. Halling
影响因子：
3.8
作者：
S. Okazaki;N. Kamiya;K. Abe;M. Goto;F. Nakashio
通讯作者：
S. Okazaki;N. Kamiya;K. Abe;M. Goto;F. Nakashio