Galactose-sensitive mutants of Salmonella II. Bacteriolysis induced by galactose

When the mutants of Salmonella lacking UDPGal-4-epimerase were grown in the presence of galactose, they exhibited marked bacteriolysis in ordinary medium and were convested to soheroplasts in hypertomic medium. Lysis was not observed in non-growing cells. Synthesis of cell wall does not seem to be inhibited by galactose at least up to 5–10 min before lysis, but cell wall synthesized in the presence of galactose had a sugar composition quite different from that formed in its absence. In the light of these findings, the mechanism of lysis was discussed, considering the metabolic consequences of the absence of epimerase.