This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Broadbent, J R Articles by Kondo, J K Search for Related Content PubMed PubMed Citation Articles by Broadbent, J R Articles by Kondo, J K Agricola Articles by Broadbent, J R Articles by Kondo, J K

 Previous Article  |  Next Article 

Appl Environ Microbiol. 1991 February; 57(2): 517-524

Genetic construction of nisin-producing Lactococcus lactis subsp. cremoris and analysis of a rapid method for conjugation.

Western Dairy Foods Research Center, Department of Nutrition and Food Sciences, Utah State University, Logan 84322-8700.

ABSTRACT

Conjugation was used to construct nisin-producing Lactococcus lactis subsp. cremoris strains. Recipients were obtained by electroporation of L. lactis subsp. cremoris strains with the drug resistance plasmid pGK13 or pGB301. A method, direct-plate conjugation, was developed in which donor and recipient cells were concentrated and then combined directly on selective media. This method facilitated transfer of the nisin-sucrose (Nip+ Suc+) phenotype from the donor strain, L. lactis subsp. lactis 11454, to three L. lactis subsp. cremoris recipient strains. Nip+ Suc+ L. lactis subsp. cremoris transconjugants were obtained at frequencies which ranged from 10(-7) to 10(-8) per donor CFU. DNA-DNA hybridization to transconjugant DNAs, performed with an oligonucleotide probe synthesized to detect the nisin precursor gene, showed that this gene was transferred during conjugation but was not associated with detectable plasmid DNA. Further investigation indicated that L. lactis subsp. cremoris Nip+ Suc+ transconjugants retained the recipient strain phenotype with respect to bacteriophage resistance and acid production in milk. Results suggested that it would be feasible to construct nisin-producing L. lactis subsp. cremoris strains for application as mixed and multiple starter systems. Additionally, the direct-plate conjugation method required less time than filter or milk agar matings and may also be useful for investigations of conjugal mechanisms in these organisms.

This article has been cited by other articles:

• Dols-Lafargue, M., Lee, H. Y., Le Marrec, C., Heyraud, A., Chambat, G., Lonvaud-Funel, A. (2008). Characterization of gtf, a Glucosyltransferase Gene in the Genomes of Pediococcus parvulus and Oenococcus oeni, Two Bacterial Species Commonly Found in Wine. Appl. Environ. Microbiol. 74: 4079-4090 [Abstract] [Full Text]