表面复合修饰纳米超顺磁性材料固定化α-淀粉酶性能研究

Magnetic nanoparticles composite-modified by deep eutectic solvents and silica for immobilization of α-amylase

以复合修饰的纳米超顺磁性Fe3O4颗粒聚集体为载体固定化α-淀粉酶,比较分析固定化α-淀粉酶及游离α-淀粉酶的酶学性能。研究固定化及游离α-淀粉酶的最适温度、最适p H、操作稳定性及基本动力学等。结果表明,固定化α-淀粉酶最适p H为7,最适温度为60℃。固定化α-淀粉酶与游离α-淀粉酶相比,具有更好的温度和酸碱的耐受性。固定化α-淀粉酶重复催化反应10次,相对酶活力仍剩余72.09%,重复操作的半衰期为18.97次,具有良好的操作稳定性。固定化α-淀粉酶的米氏常数Km值为45.31 mg/m L,亲和性弱于游离α-淀粉酶。

The composite- modified nano- superparamagnetic Fe3O4 particle aggregates as the carrier, α- amylase was immobilized by method of covalent linkage.The application performance of immobilized α-amylase and free α-amylase were studied.The temperature, pH value, the operation stability and the basic kinetics of them were compared, respectively. The results showed that optimal pH value and temperature of immobilized α-amylase were 7 and 60 ℃ ,general similar with that of free α- amylase. Compared with the free α- amylase, immobilized α- amylase had better resistance of acid, alkali and temperature.After 10 recycles, relative activity of immobilized enzyme was still remaining 72.09%, half-life period deduced 18.97 times.Immobilized α-amylase had better operation stability. Km of immobilized α-amylase was 45.31 mg/mL, and the affinity was weaker than free a-amylase.