Employing lytic phage-mediated horizontal gene transfer in Lactococcus lactis

Lactococcus lactisis a lactic acid bacterium widely used as a starter culture in the manufacture of dairy products, especially a wide variety of cheeses. Improved industrial strains would help to manufacture better food products that can meet the industry's and consumer's demands with respect to e.g. quality, taste, texture and shelf life. Bacteriophage infection ofL.lactisstarter cultures represents one of the main causes of fermentation failure and consequent economic losses for the dairy industry. In this study, however, we aim at employing bacteriophages for beneficial purposes. We developed an experimental setup to assess whether phage-mediated horizontal gene transfer could be used to enhance the genetic characteristics ofL.lactisstrains in accordance with the European law regarding the use of genetically modified organisms (GMOs) in the food industry. Although we could not show the transfer of chromosomal DNA we did successfully transduce two dissimilar plasmids fromL.lactisstrain MG1363 to one of its derivatives employing three different lactococcal bacteriophages.