Synthesis and modification of novel magnetic cellulose composite microspheres for laccase immobilization.

In this paper, an effective strategy to improve the stability and recovery convenience of immobilized laccase by preparing magnetic particles from cheap filter paper fibers was studied, that is, MC@Fe3O4 microparticles were prepared by simple cellulose regeneration and carboxyl group functionalization, and then immobilized laccase under mild conditions. The Box-Behnken design (BBD) was used to optimize the enzyme concentration, pH value and contact time affecting the immobilization yield. The results showed that the concentration of laccase and pH value had important effects on the immobilization yield. The thermal stability, pH stability and storage stability of immobilized laccase were higher than those of free enzyme. Most importantly, the immobilized laccase had a good degradation capacity for bisphenol A (BPA), with a degradation rate of 75.65 % in the first cycle, and the BPA removal rate remained above 35 % even after 8 consecutive reuses. This study developed a new magnetic cellulose material to immobilize laccase, and the immobilized laccase had great potential in BPA wastewater treatment.