The site-specific recombination system of the Lactobacillus species bacteriophage A2 integrates in Gram-positive and Gram-negative bacteria

摘要

Results are given from experiments on the genetic elements required for site-specific integration of Lactobacillus spp. bacteriophage A2; the attachment sites for the phage (attP) and bacteria (attB) and the gene that encodes the integrase. Lactobacillus spp. and Lactococcus lactis strains were grown in MRS and M17 media, respectively, and supplemented with 0.5% glucose, without aeration, at 30deg C. The non-permissive temperature for pG+host9 replication was 38, 40 and 42deg C for L. lactis, Escherichiacoli, and lactobacilli, respectively. Bacteriophage A2 was propagated on L. casei ATCC 393 or L. paracasei ATCC 27092. A plasmid-borne integration cassette was functional on the genomes of the natural hosts of the phage, on other distantly related lactic acid bacteria and on unrelated Gram-negative bacteria such as E. coli and Gram-positive bacteria such as L. lactis. Possible uses of this information in biotechnology and food and/or feed industry are discussed.