米曲霉果糖基转移酶催化合成蔗糖-6-乙酸酯

Synthesis of Sucrose-6-acetate Catalyzed by Fructosyltransferase from Aspergillus oryzae

对来自于米曲霉(Aspergillus oryzae)的果糖基转移酶催化蔗糖(s)与葡萄糖-6-乙酸酯(g-6-a)生成蔗糖-6-乙酸酯(s-6-a)的反应进行了研究。考察了底物质量比m(g-6-a)∶m(s)、反应温度、反应时间、pH、酶的质量浓度对反应的影响。单因素实验结果表明,最优的催化反应条件为:反应温度50℃、pH=6.2、m(g-6-a)∶m(s)=1∶3、反应时间48 h、酶的质量浓度为4.0 g/L。在该条件下,g-6-a的摩尔转化率可达26.69%。

The synthesis reaction of sucrose-6-acetate（s-6-a）with sucrose（s）and glucose-6-acetate（g-6-a） catalyzed by fructosyltransferase from Aspergillus oryzae was investigated.The effects of mass ratio of reactants m（g-6-a）∶m（s）,reaction temperature,reaction time,pH,mass concentration of enzyme on the reaction were examined.The one-factor experimental results showed that the optimum yield was obtained at 50 ℃,pH=6.2,m（g-6-a）∶m（s）=1∶3,reaction time 48 h and mass concentration of enzyme 4.0 g/L.On this condition the molar convert ratio of g-6-a was 26.69%.