title: Liquid-liquid extraction of commercial and biosynthesized nisin by aqueous two-phase micellar systems.
abstract: Nisin is a natural additive for conservation of food, and can also be used as a therapeutic agent. Nisin inhibits the outgrowth of spores, the growth of a variety of Gram-positive and Gram-negative bacteria. In this paper we present a potentially scalable and cost-effective way to purify commercial and biosynthesized in bioreactor nisin, including simultaneously removal of impurities and contaminants, increasing nisin activity. Aqueous two-phase micellar systems (ATPMS) are considered promising for bioseparation and purification purposes. Triton X-114 was chosen as the as phase-forming surfactant because it is relatively mild to proteins and it also forms two coexisting phases within a convenient temperature range. Nisin activity was determined by the agar diffusion assay utilizing Lactobacillus sake as a sensitive indicator microorganism. Results indicated that nisin partitions preferentially to the micelle rich-phase, despite the surfactant concentration tested, and its antimicrobial activity increases. The successful implementation of this peptide partitioning, from a suspension containing other compounds, represents an important step towards developing a separation method for nisin, and more generally, for other biomolecules of interest.
authors.affiliation: Department of Biochemical and Pharmaceutical Technology/FCF, University of São Paulo, São Paulo, Brazil.
authors.forename: A F
authors.initials: AF
authors.lastname: Jozala
authors.forename: A M
authors.initials: AM
authors.lastname: Lopes
authors.forename: P G
authors.initials: PG
authors.lastname: Mazzola
authors.forename: P O
authors.initials: PO
authors.lastname: Magalhães
authors.forename: T C
authors.initials: TC
authors.lastname: Vessoni Penna
authors.forename: A
authors.initials: A
authors.lastname: Pessoa