Search

Three different techniques for bacterial mating were applied to wild type and culture collection strains of Lactococcus lactisharbouring transposons: direct plate conjugation, filter mating and mating on milk agar. Efficiencies and frequencies of transfer were compared. Transconjugants were characterized by marker properties and molecular assays. Transposon‐coded Suc+Nis+phenotype as well as Suc+Bac+Nis–phenotype were transferred with frequencies ranging between 10−9and 10−6. Milk agar plate mating was the best technique for obtaining gene transfer events involving wild type lactococci.