Nano-magnetic cross-linked enzyme aggregates of naringinase an efficient nanobiocatalyst for naringin hydrolysis.

In this research, the preparation and characterization of a novel biocatalyst comprising nano-magnetic cross-linked enzyme aggregates of naringinase (NM-NGase-CLEAs), which was covalently bounded to lysine-assisted magnetic nanoparticles, were studied. The Schiff base formed between ɛ-amino groups of the lysine residues and aldehyde groups of glutaraldehyde was reduced by ascorbic acid. Among the six different precipitants, tert-butanol performed the best for naringin hydrolysis. The optimal conditions for the immobilization process required 10 mM glutaraldehyde, 1:10 ratio of lysine/enzyme, and 3 h crosslinking at 3-4 °C. The morphology of the NM-NGase-CLEAs implied a non-uniform, semi-pyramid and semi-cubic rods. The dynamic light scattering (DLS) results showed that the nanomagnetite particle size was around 81.9-96.5 nm, with a polydispersity index (PDI) of 0.238. After NM-NGase-CLEAS formation, the particle size was reduced to around 13.2-15.3 nm, with PDI of 0.177, respectively. Moreover, the Ȥ-potential of -28 mV also confirms the improvement of CLEAs stability. The NM-NGase-CLEAs kept 73% of its original activity after 10 cycles, which proposes strong operational stability. In conclusion, the NM-NGase-CLEAs are thermo-stable, reusable, and efficient nanobiocatalyst for debittering of citrus juices.