Effect of lysogeny on transfection and transfection enhancement in Bacillus subtilis

Abstract

Strains of B. subtilis 168 lysogenic for bacteriophage phi105 transfect with deoxyribonucleic acid (DNA) isolated from bacteriophage SPO2 at a higher efficiency than non lysogenic strains. This enhancement of transfection was not the result of recombination between bacteriophages SPO2 and phi105. Superinfection marker rescue increased transfection with DNA from bacteriophage SPO2 when infection wit eiter bacteriophage SPO2sus6 or bacteriophage phi105 occurred simultaneously with the addition of the transfecting DNA. Again, this enhancement of transfection was not the result of recombination but rather a protection of the transfecting DNA by the superinfecting bacteriophage. The ability of the superinfecting bacteriophage to protect the transfecting DNA from inactivation was maximal when the bacteria were just becoming competent. Bacteriophage phi1 cannot replicate after the transfection of competent bacteria lacking a functional DNA replication system, whereas bacteriophage phi1 was able to replicate after infection of competent bacteria grown under comparable conditions.