Abstract：
Fructansucrases produce fructans by polymerizing the fructose moiety released from sucrose. Here, we describe the recombinant expression and characterization of a unique fructansucrase from Lactiplantibacillus plantarum DKL3 that showed low sequence similarity with previously characterized fructansucrases. The optimum pH and temperature of fructansucrase were found to be 4.0 and 35 °C, respectively. Enzyme activity increased in presence of Ca2+ and distinctly in presence of Mn2+. The enzyme was characterized as an inulosucrase (LpInu), based on the production of an inulin-type fructan as assessed byNMR spectroscopy and methylation analysis. In addition to β-2,1-linkages, the inulin contained a few β-2,1,6-linked branchpoints. High-performance size exclusion chromatography with refractive index detection (HPSEC-RI) revealed the production of inulin with a lower molecular weight compared to other characterized bacterial inulin. LpInu and its inulin product represent novel candidates to be explored for possible food and biomedical applications.
摘要：
果糖蔗糖酶通过聚合从蔗糖释放的果糖部分产生果聚糖。这里,我们描述了来自植物乳杆菌DKL3的独特果糖蔗糖酶的重组表达和表征，该酶与先前表征的果糖蔗糖酶显示出低序列相似性。发现果聚糖蔗糖酶的最佳pH和温度为4.0和35°C，分别。在Ca2存在下，酶活性增加，在Mn2存在下明显增加。该酶的特征是inulosurecrase（LpInu），基于通过NMR光谱和甲基化分析评估的菊粉型果聚糖的生产。除了β-2,1-键，菊粉含有一些β-2,1,6连接的分支点。具有折射率检测的高效尺寸排阻色谱法（HPSEC-RI）显示，与其他表征的细菌菊粉相比，菊粉的分子量较低。LpInu及其菊粉产品代表了可能用于食品和生物医学应用的新型候选物。
