We develop a new type of shallow porous microsphere carriers with core-shell structure by using glass beads as cores, chitosan as coating layer, glutaraldehyde as cross-linking agent and stearic acid powder as porogen. The characterization of FT-IR, SEM, XRD, TGA-DSC and XPS demonstrates that the modification in each step is feasible and chitosan forms a uniformly coated graft layer on the surface, accounting for 40 % of the total weight. Then, this study focuses on immobilization of inulinase on the shallow porous microsphere carriers. The optimal conditions for immobilization are: pH value is 5.0; cross-linking time is 2.5 h; the molar ratio of free enzyme, glutaraldehyde and carrier amino group is 5.0 × 10⁻³:0.3:1. Among them, pH value has the most significant influence on the reaction process. The prepared immobilized inulinase preserves 73 % activity of free inulinase, and the suitable ranges of pH and temperature widen. Thermal stability experiments are operated at 70 °C for 3 h, when immobilized inulinase still maintains 69.20 % of initial activities whereas free inulinase only maintains 33.79 %. The immobilized inulinase still maintains 77.93 % of initial activities after 10 reuses, and its calculated half-life is 22 times, demonstrating developmental potential in industrial application.

我们以玻璃珠为核，壳聚糖为包衣层，戊二醛为交联剂，硬脂酸粉为致孔剂，开发了一种新型的核壳型浅孔微球载体。FT-IR，SEM，XRD，TGA-DSC和XPS的表征表明，在每个步骤中进行修饰都是可行的，壳聚糖在表面形成均匀涂覆的接枝层，占总重量的40％。然后，本研究着重将菊粉酶固定在浅层多孔微球载体上。固定化的最佳条件是：pH值为5.0；交联时间为2.5小时；游离酶，戊二醛和载体氨基的摩尔比为5.0×10 ^-3：0.3：1。其中，pH值对反应过程影响最大。制备的固定化菊粉酶保留了游离菊粉酶73％的活性，合适的pH和温度范围变宽。当固定化菊粉酶仍保持初始活性的69.20％，而游离菊粉酶仅保持33.79％时，热稳定性实验在70°C下进行3小时。固定的菊粉酶在重复使用10次后仍可保持77.93％的初始活性，其半衰期为22倍，证明了其在工业应用中的发展潜力。