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米曲霉 ( Aspergillus oryzae)发酵液经硫酸铵分级沉淀、DEAE-cellulose DE-5 2吸附洗脱、DEAE-Sephadex A-5 0柱层析、Sephadex G-2 0 0凝胶过滤及羟基磷灰石吸附柱层析等步骤 ,得到了聚丙烯酰胺凝胶电泳均一的低聚果糖转移酶。得率 4.4% ,比活力为 3 5 15 u/mg,纯化了 15 5 5倍。分子量为 7.89× 10 4。低聚果糖转移酶最适 p H为 6.3 ,最适温度 60℃ ,热稳定性较好 ,对底物蔗糖的 Km 值为 0 .65 mol/L
Aspergillus oryzae fermentation broth was fractionated by ammonium sulfate, eluted by DEAE-cellulose DE-5 2, gel-fractionated on DEAE-Sephadex A-50, gel filtration on Sephadex G- Adsorption column chromatography and other steps, polyacrylamide gel electrophoresis was uniform oligofructosyl transferase. The yield was 4.4%, the specific activity was 3 5 15 u / mg and the purity was 15 5 5 times. The molecular weight is 7.89 × 10 4. The optimum pH of fructooligosaccharyl transferase was 6.3, the optimal temperature was 60 ℃, and the thermostability was good. The Km value of substrate fructose was 0.65 mol / L