Sustainable chiral separation using chitin nanofibrous microspheres for enhanced catalysis and reusability

The inefficiency and instability of free enzymes in the chiral separation of high-purity D-pantolactone, a crucial intermediate in vitamin B5 synthesis, pose significant challenges, with nanostructured materials offering promising solutions. In this study, D-Lactonohydrolase (D-lacs) was immobilized in crab-derived chitin nanofibrous microspheres (ChNFM), achieving high enzyme loading and excellent reusability. By combining physical absorption and chemical cross-linking, stable immobilization of D-lacs was realized. The enzyme loading capacity of D-Lacs on ChNFM was gradually increased as the particle size of ChNFM decreased. Batch hydrolysis using D-Lacs@ChNFM was conducted for 50 consecutive times, maintaining an average degree of hydrolysis of 30.0%, with stable enzyme activity throughout. Compared to the commercial immobilized D-lacs carrier, D-Lacs@ChNFM exhibited superior hydrolytic efficiency, higher batch stability, and excellent biodegradability. This work highlights the potential of ChNFM as an efficient and eco-friendly carrier for enzyme immobilization, offering a promising platform for scalable DL-pantolactone separation and greener vitamin B5 production.