Low-cost purification of nisin from milk whey to a highly active product

• Published in: Food and bioproducts processing 2015-01, Vol.93, p.115-121
• Main Authors: Jozala, Angela Faustino, de Lencastre Novaes, Letícia Celia, Mazzola, Priscila Gava, Oliveira-Nascimento, Laura, Vessoni Penna, Thereza Christina, Teixeira, José António, Passarinha, Luis António, Queiroz, João António, Pessoa, Adalberto
• Format: Article
• Language: English
• Subjects: Ammonium sulfate; Antimicrobial activity; Bacteria; Elution; Foods; Hydrophobic interaction chromatography (HIC); Lactococcus lactis; Milk; Milk whey; Nisin; Purification; Science & Technology; Whey
• ISSN: 0960-3085; 1744-3571
• DOI: 10.1016/j.fbp.2013.12.003

•It was established a cost-effective purification of nisin from milk whey.•Purified nisin contained high antimicrobial activity and low salt (water elution).•It was obtained as highly purified nisin, up to 775-fold more active than crude extract.•Purification of milk whey provides nisin with high activity which can further be applied to a variety of areas. Nisin is a natural peptide used as a preservative in a variety of food products, in which it inhibits mainly Gram-positive bacterial growth, including multidrug-resistant pathogens. However, its application range depends on the cost-effective production and purification of this molecule. Our group has previously produced nisin by Lactococcus lactis cultivation in milk whey, which is an industrial residue from dairy production. To our knowledge, no report used milk whey as a culture medium, although several investigators have purified nisin using different techniques. We thus aimed to establish a low-cost purification of nisin obtained by this process. Samples were diluted in ammonium sulphate, applied onto HIC columns (butyl sepharose CL 4B matrix), and eluted with Milli-Q water or PBS. Elution fractions were monitored for protein content and nisin antibacterial activity. Water elution resulted in purification factor values (270, commercial nisin; 775, nisin produced in-house) higher than those obtained with PBS elution. We concluded that purification of nisin does not require precipitation with ammonium sulphate, therefore allowing step/cost reduction. Moreover, purification from milk whey using HIC provides nisin with high activity and low salt content, which can further be applied to a variety of areas.