Simultaneous conjugal transfer in Lactococcus to genes involved in bacteriocin production and reduced susceptibility to bacteriophages

Summary

Conjugal matings were performed between Lactococcus lactis DRC1 (a lactose-fermenting (Lac⁺), bacteriocin-producing (Bac⁺) strain) and L. lactis HID113 (Lac⁻ Bac⁻). Transconjugant derivatives of HID113 were identified on the basis of lactose fermentation, resistance to the DRC1 bacteriocin (dricin) or reduced sensitivity to phage sk1. Regardless of how they were identified, all transconjugants gave fewer and smaller plaques with phages c2 and sk1 than did HID113. All but one of 275 transconjugants tested also produced dricin, suggesting some functional relationship or close genetic linkage between the reduced phage sensitivity and dricin production and resistance.

Lactococcus lactis, Bacteriocin, Bacteriophage resistance, Conjugation, DRC1

Author notes

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C.S.I.R.O. Division of Biomolecular Engineering, Parkville, Victoria 3052, Australia.