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 of β-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.
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