Identification of Lactoce Plasmids in Lactococcus lastic subsp. lactis Stains

Plasmids encoding lactic acid fermentation ability were investigated in 50 strains of L. lactis subsp. lactis. Acriflavine was used for the elimination of lactose fermentation ability (Lac + ) from wild type strains. Lactose negative (Lac - ) mutants were selected on lactose indicator agar media. Six different lactose plasmids were identified for fifty strains by comparison of plasmid profiles of Lac - and Lac + mutants. The molecular sizes of these lactose plasmids ranged between 26.3 and 38.5 kb.

Identification of Lactoce Plasmids in Lactococcus lastic subsp. lactis Stains

Plasmids encoding lactic acid fermentation ability were investigated in 50 strains of L. lactis subsp. lactis. Acriflavine was used for the elimination of lactose fermentation ability (Lac + ) from wild type strains. Lactose negative (Lac - ) mutants were selected on lactose indicator agar media. Six different lactose plasmids were identified for fifty strains by comparison of plasmid profiles of Lac - and Lac + mutants. The molecular sizes of these lactose plasmids ranged between 26.3 and 38.5 kb.