Rapid purification of nisin Z using specific monoclonal antibody-coated magnetic beads

A rapid method is described for the isolation and purification of nisin Z f rom Lactococcus lactis subsp. Inc tis biovar. diacetylactis UL719 culture s upernatant using magnetic beads. Anti-nisin Z monoclonal antibodies were co valently bound to EDC-activated magnetic beads and the complex was incubate d overnight at 4 degreesC with the culture supernatant. Bound nisin Z was t hen eluted with urea 6 M formic acid 0.1 M mixture. Using this procedure, a high yield of 61.5% was obtained with a nisin Z specific activity of 2.4 x 10(4) IU mg(-1). Magnetic beads were re-used for two other purification cy cles during which a significant decrease of purification yield from 61.5 tu 26.7% was observed. The immunomagnetic purification strategy developed in this work was shown to be efficient and offers an alternative rapid procedu re fur production of high-purity food-grade nisin Z. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.