Immobilization of laccase by 3D bioprinting and its application in the biodegradation of phenolic compounds.

Due to the increasing quantities of phenolic compounds present in wastewater, the use of enzymatic degradation with the laccase has attracted much attention as a green option for their removal. In this work, we developed a novel immobilization technology using 3D bioprinting for laccase immobilization. The hydrogel mechanism properties were optimized by experimenting with different component ratios of sodium alginate (SA), acrylamide (AM), and hydroxyapatite (HA). The improved mechanism properties were validated by morphology pictures and rheology characteristics. The optimal AM:HA:SA ratio was determined to be 4:1.2:1. We then employed an extrusion-based bioprinting technique to prepare the immobilized laccase. The substrate conversion was increased with the addition of HA, which improved the permeability of the matrix, and proved to be suitable for immobilization. The resulting immobilized laccase was used for the biodegradation of p-chlorophenol. The effects of the initial substrate concentration, pH, and temperature were evaluated. The immobilized laccase exhibited good storage stability and reusability, retaining over 80% of its initial activity after 72 h of storage, and was able to be reused for seven batches. These results highlight that the immobilized laccase prepared by 3D bioprinting has great potential for use in the biodegradation of phenolic compounds.