大孔树脂MI-BN4固定化β-呋喃果糖苷酶Fru6及催化合成低聚果糖

Immobilization of β-fructofuranosidase Fru6 by macroporous resin MI-BN4 and its application in catalytic synthesis of fructo-oligosaccharides

为了降低β-呋喃果糖苷酶Fru6使用成本,使β-2,6键型低聚果糖应用到实际中。该试验研究了对Fru6的固定化技术。通过多官能团树脂MI-BN4对Fru6进行固定化,优化了果糖苷酶Fru6固定化条件,并研究固定化酶Fru6酶学性质、固定化酶Fru6催化低聚果糖能力、以及固定化酶Fru6重复使用的能力。在吸附时间6 h,温度25℃,加酶量40 U的条件下进行固定化,可得到酶活力205.7 U/g,酶活回收率95.2%,蛋白吸附量0.6 mg/g干树脂的固定化果糖苷酶。固定化酶Fru6催化合成低聚果糖能力相较于游离酶有所提高,低聚果糖转化率从62%提升到了72%,并且可重复使用12次,低聚果糖产量略有降低。得到了高酶活回收率且催化能力较好的固定化果糖苷酶,为生产6-低聚果糖奠定了基础。

In order to reduce the running cost,immobilization ofβ-fructofuranosidase Fru6 was investigated for fructo-oligosaccharide preparation.Fru6 was immobilized by multi-functional resin MI-BN4 and the immobilization condition was optimized.The enzymatic properties,the ability to catalyze fructo-oligosaccharide and the capacity for reusing immobilized Fru6 were explored.When adsorbed for 6 h at 25°C with 40 U enzyme,an immobilized enzyme with 205.7 U/g activity was obtained,which had 95.2%recovery rate of enzyme activity and absorbed 0.6 mg/g dry resin protein.Compared with free enzyme,the fructo-oligosaccharides conversion rate with immobilized Fru6 increased from 62%to 72%and the yield of fructo-oligosaccharides slightly reduced.Besides,the immobilized Fru6 could be reused for 12 times.Overall,the immobilized Fru6 has high enzyme activity recovery rate and good catalytic ability,which lays a foundation for fructo-oligosaccharides production.