One step purification of active nisin by electrodialysis from a commercial product

Abstract

Nisin is a natural antimicrobial peptide widely used in food and medical applications. Its use is hampered by its costly production process and complex further purification. Therefore, electrodialysis process was used, for the first time, to purify a commercial nisin solution, in comparison with a conventional multiple-step centrifugation approach. Electrodialysis was, in one purification step, as efficient as the centrifugation process for nisin desalination (demineralization rate of 95.6% vs 94.3–99.8% respectively) with a higher protein recovery yield (83.8% vs 12.5–42.1% respectively). Centrifugation at higher concentration allowed the purification of nisin with the highest specific activity for supernatants S2 (3653.8–7307.6 AU/mg of proteins) and S3 (2394.2–9577.3 AU/mg of proteins). In a circular economy scheme, since saline effluents produced during centrifugation and precipitation processes represent an ecological and economical hurdle regarding their disposal, the use of electrodialysis would be of interest, by reusing the salts and lowering or eliminating the production of by-products.