Cloning and expression of a plasmid-linked pediocin determinant trait of Pediococcus acidilactici F

Plasmid DNA from Pediococcus acidilactici F was prepared by lysozyme-mutano lysin method and purified by cesium chloride-ethidium bromide (CsCl-EtBr) d ensity gradient ultracentrifugation. Agarose gel electrophoresis of plasmid DNA and plasmid-curing experiments suggested that bacteriocin activity was harboured on a small plasmid of approximately 9.1 kb (kilobasepair) in Ped iococcus acidilactici F. Plasmid encoding bacteriocin production in P. acid ilactici F was examined for restriction enzyme cleavage patterns and its ma p has been constructed. An Escherichia coli strain transformed with the rec ombinant plasmid, pQE322, produced and, most probably, secreted pediocin F.