High Frequency Intergeneric and Intrageneric Conjugal Transfer of Drug Resistance Plasmids in Leuconostoc mesenteroides ssp. cremoris

¹ Department of Food Science, Purdue University, West Lafayette, IN 47907

Transfer of the broad host range conjugative plasmids pAMß1, pVA797:: Tn917, and pIP501 between Lactococcus lactis and Leuconostoc mesenteroides ssp. cremoris occurred at high frequency via a conjugation-like process on solid surface agar. Frequencies of 10^–1 to 10^–3 transconjugants per input donor cell were observed from L. lactis to three strains of Leuc. mesenteroides ssp. cremoris. Reverse intergeneric transfer from Leuc. mesenteroides ssp. cremoris to L. lactis occurred at frequencies up to 10^–4 transconjugants per donor cell. Intrageneric transfer between Leuc. mesenteroides ssp. cremoris strains was also observed at frequencies as high as 10^–3 transconjugants per donor cell. The ability to transfer these plasmids to and among Leuc. mesenteroides ssp. cremoris at high frequencies provides a method of genetic transfer, making them available to cloning strategies developed in other Gram-positive bacteria.

Key Words: Leuconostoc • conjugation • plasmids

Submitted on February 1, 1991
Accepted on April 4, 1991