College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan, 430081, China.
Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan University of Science and Technology, Wuhan, 430081, Hubei, China.
Bioprocess Biosyst Eng. 2023 Nov;46(11):1591-1611. doi: 10.1007/s00449-023-02922-0. Epub 2023 Sep 1.
Rape straw was used as the raw material for the biochar in this study, which was then changed using acid, alkali, and magnetic techniques. The laccase was attached using the adsorptions-crosslinking process, and the three modified biochars served as the carriers. The ideal circumstances for laccase immobilization were explored, and both biochar and immobilized laccase's characteristics were examined. The removal of 2,4-dichlorophenol (2,4-DCP) by immobilized laccase from modified biochar and its degradation products were researched. The main conclusions are as follows: the optimal concentration of glutaraldehyde (GLU) was 4%, and the pH was four, and the enzyme dosage was 1.75 mg/mL for the immobilized laccase of acid-modified biochar (SBC@LAC). The optimal concentration of GLU was 5%; the pH was four, and the enzyme dosage was 2 mg/mL for immobilized laccase from alkali-modified biochar (JBC@LAC). The optimal concentration of GLU was 5%; the pH was four, and the enzyme dosage was 1.75 mg/mL for immobilized laccase from magnetically modified biochar (CBC@LAC). SEM images could show the changes in the surface morphology of biochar caused by three modification methods. The BET results demonstrated that acid and magnetic modification increased the specific surface area of biochar, and alkali modification mainly expanded the pore size of biochar. FT-IR and XRD showed that modification and laccase loading had little effect on the structure of biochar. The stability of immobilized laccase was better than that of free laccase in acid-base, heat, and storage. Among the three modified biochar immobilized laccases, JBC@LAC showed the best acid-base stability and thermal stability, and the relative enzyme activity changed the least when pH and temperature conditions changed. The storage stability of SBC@LAC is the best. After 30 days of storage, the relative enzyme activity is still 83%. The removal rates of 2,4-DCP were 57, 99, and 63%, respectively, by SBC@LAC, JBC@LAC, and CBC@LAC. After five reuses, the removal rates of 2,4-DCP by SBC@LAC, JBC@LAC and CBC@LAC were 26, 42, and 27%, respectively. The intermediate products of 2,4-DCP degradation by immobilized laccase were p-phenol, p-benzoquinone and maleic acid.
稻草被用作本研究生物炭的原料，然后使用酸、碱和磁技术进行改性。通过吸附交联法将漆酶附着在上面，然后将三种改性生物炭作为载体。探索了漆酶固定化的理想条件，并研究了生物炭和固定化漆酶的特性。研究了固定化漆酶从改性生物炭中去除 2,4-二氯苯酚（2,4-DCP）及其降解产物的情况。主要结论如下：酸改性生物炭固定化漆酶（SBC@LAC）的最佳戊二醛（GLU）浓度为 4%，pH 值为 4，酶用量为 1.75 mg/mL。碱改性生物炭固定化漆酶（JBC@LAC）的最佳 GLU 浓度为 5%，pH 值为 4，酶用量为 2 mg/mL。磁改性生物炭固定化漆酶（CBC@LAC）的最佳 GLU 浓度为 5%，pH 值为 4，酶用量为 1.75 mg/mL。SEM 图像可以显示三种改性方法引起的生物炭表面形貌变化。BET 结果表明，酸和磁改性增加了生物炭的比表面积，而碱改性主要扩大了生物炭的孔径。FT-IR 和 XRD 表明，改性和漆酶负载对生物炭的结构影响不大。固定化漆酶的稳定性优于游离漆酶的酸碱、热和储存稳定性。在三种改性生物炭固定化漆酶中，JBC@LAC 表现出最好的酸碱稳定性和热稳定性，当 pH 值和温度条件改变时，相对酶活性变化最小。SBC@LAC 的储存稳定性最好。储存 30 天后，相对酶活性仍为 83%。SBC@LAC、JBC@LAC 和 CBC@LAC 对 2,4-DCP 的去除率分别为 57%、99%和 63%。重复使用五次后，SBC@LAC、JBC@LAC 和 CBC@LAC 对 2,4-DCP 的去除率分别为 26%、42%和 27%。固定化漆酶降解 2,4-DCP 的中间产物为对苯二酚、对苯醌和马来酸。
