Abstract: A method of laccase immobilization was developed by ZrO₂ synthesized via biomineralization, which was prepared by encapsulating laccase in the zirconia nanoparticles with the lysozyme as the inducer, and the recovery rate of enzyme activity was 59%. Field emission scanning electron microscope (FESEM), energy dispersive spectrometer (EDS), and thermal gravimetric analyzer (TGA) were used to characterize ZrO₂ nanoparticles before and after the enzyme immobilization. The results proved that laccase was immobilized in ZrO₂ successfully and lysozyme was not only induced the formation of zirconia but also acted as a biological template encapsulated by ZrO₂. Enzymatic properties of immobilized laccase by biomimetic synthesis were also explored. The optimum pH and temperature of immobilized laccase were 3 and 70℃, respectively. Compared with free enzyme, the pH and temperature stability of immobilized laccase were significantly increased. The activity of the immobilized laccase was 95% of the original activity after storing for 30 days at 4℃, and the activity was still 60% of the initial enzyme activity after recycling 5 times. Moreover, the immobilized laccase was used in the decolorization of malachite green and the experimental result showed that the decolorization rate of the malachite green was more than 95% within 6h. Additionally it proved that the immobilized laccase decolorized malachite green by both of adsorption and degradation effects through the UV-visible spectroscopy analysis.

Key words: biomemitic synthesis, zirconium oxide, enzyme, immobilization, nanomaterials, malachite green

摘要： 以溶菌酶作为诱导剂，仿生合成了ZrO₂固定化漆酶纳米颗粒，其酶活回收率达59%，采用场发射扫描电子显微镜（FESEM）、能谱仪（EDS）、热重分析仪（TGA）等手段对ZrO₂纳米颗粒及ZrO₂固定化漆酶颗粒进行表征，结果表明漆酶可成功固定到ZrO₂颗粒中，同时还证明了溶菌酶既作为诱导剂催化ZrO₂的形成，又作为生物模板同酶一起包埋在ZrO₂颗粒中。固定化漆酶的最适pH为3，最适温度为70℃，相比于游离酶，其pH、温度稳定性都有明显提高；固定化漆酶纳米颗粒在4℃下储存30d，活性为初始酶活的95%，重复使用5次，固定化酶的残余酶活力仍有60%。此外，固定化漆酶在6h内对孔雀石绿染料的脱色率高达95%以上，通过紫外-可见吸收光谱分析（UV-vis）可知，固定化漆酶对孔雀石绿染料的处理是由吸附和降解联合作用引起的脱色。

关键词: 仿生合成, 氧化锆, 酶, 固定化, 纳米材料, 孔雀石绿