Horseradish peroxidase (HRP) was immobilized on the poly(2-hydroxyethyl methacrylate-glycidyl methacrylate) [p(HEMA-GMA)] cryogel and used for the degradation of a benzidine containing azo dye (i.e., Direct Blue-6). The maximum amount of HRP loading was found to be 87.6 mg g⁻¹ cryogel, and the retained immobilized HRP activity was 67% with respect to the same quantity of the free enzyme. Biochemical properties of the HRP preparations were also evaluated along with the stability studied under various denaturizing conditions. The toxicity of the Direct Blue-6 and its degradation products was tested using Daphnia magna. Decrease in the absorbance of the blue color of dye at 590 nm was observed during enzymatic degradation studies. Additionally, Chlorella vulgaris was used as a test organism in the algal growth inhibition studies. After 60 min reaction time, the Direct Blue-6 dye and its degradation product were enzymatically removed from the medium. Thus, after treatment with HRP approximately 60-min, the medium was non-toxic for both D. magna and C. vulgaris. The Direct Blue-6 dye and its degradation product toxicities were reduced after enzymatic treatment from 99.6 to 7.3%. It should be noted that the initial degradation products appeared to be extra toxic compared to the pristine dye.

将辣根过氧化物酶（HRP）固定在聚（甲基丙烯酸2-羟乙酯-甲基丙烯酸缩水甘油酯）[p（HEMA-GMA）]冷冻凝胶上，并用于降解含联苯胺的偶氮染料（即直接蓝6）。发现最大HRP负载量为87.6mg g ^-1冷冻凝胶，并且相对于相同量的游离酶，保留的固定化HRP活性为67％。还评估了HRP制剂的生化特性以及在各种变性条件下研究的稳定性。使用大型蚤（Daphnia magna）测试了Direct Blue-6及其降解产物的毒性。在酶促降解研究期间，观察到染料蓝色在590 nm处的吸光度降低。此外，小球藻在藻类生长抑制研究中将其用作测试生物。反应60分钟后，从培养基中酶促去除Direct Blue-6染料及其降解产物。因此，在用HRP处理约60分钟后，该培养基对D. magna和C. vulgaris均无毒。酶处理后，直接蓝6染料及其降解产物的毒性从99.6％降低到7.3％。应当指出，与原始染料相比，最初的降解产物似乎具有更高的毒性。