Laccases are versatile oxidases that are capable of decolorizing various synthetic dyes. Recombinant Bacillus amyloliquefaciens laccase was immobilized as magnetic cross-linked enzyme aggregates (M-CLEAs) for application in dye decolorization. Several parameters influencing the activity recovery were evaluated during the synthesis of M-CLEAs. With ammonium sulfate as precipitant, maximum activity was recovered by cross-linking with 0.16% glutaraldehyde for 1 h. The prepared M-CLEAs exhibited improved activity under alkaline conditions. It remained 74% activity after incubation at 60 °C for 5 h. Enhanced tolerance towards NaCl was also observed for the M-CLEAs, with 68% activity remaining in the presence of 1 M NaCl. The immobilized laccase could rapidly decolorize more than 93% of reactive black 5 and indigo carmine in 1 h, while its catalytic efficiency towards reactive blue 19 was relatively low. After four cycles of consecutive reuse, the M-CLEAs could decolorize 92% of indigo carmine. The easy recovery and reusability of M-CLEAs facilitate the potential application of bacterial laccase in dye decolorization.

漆酶是多功能氧化酶，能够使各种合成染料脱色。重组解淀粉芽孢杆菌漆酶被固定为磁性交联酶聚集体（M-CLEAs），用于染料脱色。在 M-CLEA 的合成过程中评估了影响活性恢复的几个参数。以硫酸铵为沉淀剂，通过与 0.16% 戊二醛交联 1 小时可恢复最大活性。制备的 M-CLEAs 在碱性条件下表现出更高的活性。在 60°C 下孵育 5 小时后，它仍保持 74% 的活性。还观察到 M-CLEA 对 NaCl 的耐受性增强，在 1 M NaCl 存在下仍有 68% 的活性。固定化漆酶可在 1 小时内快速脱色 93% 以上的活性黑 5 和靛胭脂，而其对活性蓝 19 的催化效率相对较低。连续重复使用四个循环后，M-CLEAs 可以使 92% 的靛蓝胭脂红脱色。M-CLEAs 的易回收性和可重复使用性促进了细菌漆酶在染料脱色中的潜在应用。