Transfection of the Anaerobe Bacteroides thetaiotaomicron with Phage DNA

SUMMARY: The properties of a Bacteroides thetaiotaomicron phage, β1, are described. Phenol-extracted phage β1 DNA transfects Ca2+-treated B. thetaiotaomicron cells and transfection is not limited to a particular stage in the growth cycle. An obligatory step in the transfection procedure is a 33-fold dilution in broth, allowing replication of the infected cells. Prolonged incubation of treated cells with DNA prior to dilution in broth results in a large decrease in phage titre. The application of this system to the investigation of the genetics of obligate anaerobes is discussed.