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Improvement of phage defence in Lactococcus lactis by introduction of the plasmid encoded restriction and modification system Lla AI
Author(s) -
Gabs S.,
Josephsen J.
Publication year - 2003
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1046/j.1472-765x.2003.01320.x
Subject(s) - lactococcus lactis , plasmid , bacteriophage , starter , microbiology and biotechnology , biology , fermentation starter , nisin , bacteria , strain (injury) , food science , escherichia coli , genetics , antimicrobial , gene , lactic acid , anatomy
Aims: To study the ability of the plasmid‐encoded restriction and modification (R/M) system Lla AI to function as a bacteriophage resistance mechanism in Lactococcus lactis during milk fermentations. Methods and Results: Plasmid pAIcat4, carrying the R/M system Lla AI and a chloramphenicol resistance cassette, was introduced into the plasmid‐free strain L. lactis MG1614 and the industrial strain L. lactis 964. By measuring changes in conductivity the influence of different phage on the growth was determined. Conclusions: The plasmid‐encoded R/M system Lla AI significantly improves the bacteriophage resistance of L. lactis during milk fermentations. Significance and Impact of the Study: It is essential to determine the potential of a phage defence mechanism in L. lactis starter culture strains during growth in milk before steps are taken to improve starter cultures. This study shows that Lla AI is useful for improvement of starter cultures.