酪氨酸酶固定化碳材料对苯酚的生物降解性能

Biodegradation Property of Phenol Using the Immobilized Tyrosinase on Carbon Material

以新型碳材料氧化石墨烯作为载体,利用共价结合方法制备酪氨酸酶固定化氧化石墨烯复合物,并利用该复合物对苯酚进行催化降解,探讨酶的加载特性和酶的催化活性,以及固定化酪氨酸酶催化降解苯酚的最优条件及储存稳定性。通过对固定化酪氨酸酶进行活性和固定量分析后认为:单位质量载体的酶固定量为1.78 mg/mg,单位质量载体的酶活性为1 880.6 U/mg;固定化酪氨酸酶在30h内对47.06mg/L苯酚的降解率可达86.3%,降解反应的最优条件为pH=7.0、温度=25℃;固定化酪氨酸酶在4℃条件下30d后仍保持初始活性的77.7%,其稳定性优于游离酪氨酸酶。另外,在氧化石墨烯上引入磁颗粒,既简化了酶固定流程,又能做到回收利用。

Graphene oxide,a novel carbon material,was employed as the supporting material for the immobilization of tyrosinase enzymes with covalent bonding method.Loading dosage,enzyme activity,optimal conditions for phenol degradation and storage stability of the immobilized tyrosinase wereinvestigated.Loading yield and enzyme activity of immobilized tyrosinase could reach 1.78 mg/mg support and 1 880.6 U/mg support,respectively.The phenol degradation efficiency by immobilized tyrosinase was 86.3%in 30 hreaction and the optimal conditions of phenol degradation were at pH 7.0 and 25℃.Comparing with the free tyrosinase,the immobilized tyrosinase had better storage stability by retaining 77.7% of initial activity for at least 30 days when stored at 4℃.With the introduced magnetic particles in the surface of graphene oxide,the process of enzyme immobilization could be simplified and it is helpful for reuse.