多孔HZIF-8固定化酶及其降解苯酚的性能研究

Study on porous HZIF-8 immobilized enzyme and its performance in phenol degradation

以水凝胶为模板,采用模板乳化法制备锌基MOF材料HZIF-8,利用包埋法和交联法相结合的方法固定辣根过氧化物酶,研究温度、pH以及苯酚浓度对HZIF-8固定化酶降解苯酚的影响。结果表明,HZIF-8固定化酶的最适温度为50℃,最适pH为7,环境耐受力远高于游离酶,半衰期为16 d。放置10 d时,相对酶活性仍达82%,124.64 U/mg。HZIF-8固定化酶最佳降解苯酚条件:50℃,pH=8。重复回收使用6次,相对酶活仍达到50%以上。酸根过氧化物酶(HRP)与HZIF-8固定化酶的K m值分别为9.57 mmol/L和5.69 mmol/L。HZIF-8固定化酶对底物的亲和力高于游离酶,其催化效率相对游离HRP有所提升,固定化酶的操作稳定性和酶活性也显著增强。

Using hydrogel as template,zinc based MOF material HZIF-8 was prepared by template emulsification method,and horseradish peroxidase was immobilized by the combination of embedding method and cross-linking method.The effects of temperature,pH and phenol concentration on the degradation of phenol by HZIF-8 immobilized enzyme were studied.The results showed that the optimum temperature of immobilized enzyme was raised to 50℃,and the optimum pH was 7.The environmental tolerance of HZIF-8 immobilized enzyme was much higher than that of free enzyme.The half-life is 16 d.When the immobilized enzyme was placed for 10 d,the relative enzyme activity still reached 82%,124.64 U/mg.The best degradation condition of HZIF-8 immobilized enzyme:50℃,pH=8.The relative enzyme activity was still above 50%after 6 times of recycling.The K m values of acid radical peroxidase(HRP)and HZIF-8 immobilized enzyme were 9.57 mmol/L and 5.69 mmol/L,respectively.The affinity of HZIF-8 immobilized enzyme to substrate is higher than that of free enzyme,its catalytic efficiency is higher than that of free HRP,and the operational stability and activity of immobilized enzyme are also significantly enhanced.