Conjugal transfer and characterization of bacteriocin plasmids in group N (lactic acid) streptococci.

摘要: Thirteen bacteriocin-producing strains of group N (lactic acid) streptococci were screened for their potential to transfer this property by conjugation Streptococcus lactis subsp. diacetylactis Bu2-60. Bacteriocin production in three was plasmid encoded as shown conjugal and analysis cured, bacteriocin-negative derivatives the donor transconjugants. With cremoris 9B4 4G6 S. 6F7 donors, transconjugants isolated with frequencies ranging from ca. 2 X 10(-2) 10(-1) per recipient cell. Bacteriocin-producing had acquired a 39.6-megadalton 4G6, 75-megadalton strain 6F7. As restriction endonuclease analysis, plasmids almost identical. The yielded some additional fragments not present two other plasmids. In hybridization experiments any strongly hybridized each bacteriocin but nontransmissible strains. Homology also detected variety cryptic lactic acid streptococci.