Annals of Microbiology

, Volume 63, Issue 3, pp 951–956

Construction of Lactococcus lactis thyA-null using the Red recombination system

Authors

  • Xinxi Gu
    • College of Food Science and TechnologyAgricultural University of Hebei
  • Chen Li
    • College of Food Science and TechnologyAgricultural University of Hebei
  • Yi Cai
    • College of Food Science and TechnologyAgricultural University of Hebei
  • Hui Dong
    • College of Food Science and TechnologyAgricultural University of Hebei
  • Wentao Xu
    • College of Food science and Nutritional EngineeringChina Agricultural University
    • College of Food Science and TechnologyAgricultural University of Hebei
  • Jianguo Yang
    • Institute of MicrobiologyChinese Academy of Sciences
Original Article

DOI: 10.1007/s13213-012-0548-y

Cite this article as:
Gu, X., Li, C., Cai, Y. et al. Ann Microbiol (2013) 63: 951. doi:10.1007/s13213-012-0548-y

Abstract

Lactococcus lactis—a food-grade nonpathogenic lactic acid bacterium—is used widely in the food industry. In this report, we describe an approach to construct deficient strains in L. lactis utilizing the λ-Red recombination system. Three kinds of recombinant proteins, λ exonuclease, β protein and γ protein, were induced by l-arabinose in L. lactis MG1363 harboring the plasmid pKD46. A chloramphenicol-resistant cassette was amplified from pGj103 containing homology arms of 50 nt to the thyA gene. The PCR-generated DNA fragment was then electroporated into L. lactis MG1363, which expressed the recombination proteins. ThyA-null strains resistant to chloramphenicol were obtained and their growth characteristics were analyzed in relation to thymidine requirement. The results revealed that the thyA gene in L. lactis MG1363 was successfully knocked out. This is the first time that the Red system has been used in a Gram-positive bacterium, and use of the techniques presented here should prompt rapid and efficient mutagenesis or modification of L. Lactis chromosomal genes.

Keywords

Red recombinant system Gene knock-out Lactococcus lactis thyA

Copyright information

© Springer-Verlag and the University of Milan 2012