Immobilization of ω-transaminase by magnetic PVA-Fe3O4 nanoparticles

• Core–shell composite Fe3O4-PVA was prepared successfully by chemical co-precipitation, and it has a good characterization results.
• Fe3O4-PVA was firstly and successfully used to immobilize ω-TA.
• ω-TA which immobilized onto Fe3O4-PVA could be successfully separated and reused for many times in biotransformation with its activity no declined.

ω-Transaminase (ω-TA) as a kind of important biocatalyst is widely used in preparation of chiral intermediates. In this paper, a magnetic PVA-Fe3O4 nanoparticles was prepared and employed on immobilization of ω-TA to reduce the cost, increase reusability and enhance stability. The prepared magnetic PVA-Fe3O4 nanoparticles were characterized by transmission electron microscope (TEM), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The average size of magnetic PVA-Fe3O4 nanoparticles was located between 30–40 nm ω-TA was immobilized onto magnetic PVA-Fe3O4 nanoparticles via glutaraldehyde cross-linking, achieving a wider pH range as 6–8 and also a better thermal stability at 60 °C. Meanwhile, the immobilized ω-TA could be successfully reused for 13 times in biotransformation. These results therefore indicated that the immobilized ω-TA with high stability might be readily utilized in industrial purposes.