Cell division in Escherichia coli septation during synchronous growth

Summary

The capacity of E. coli B/r to support recombination and complementation between T4am phages during its life cycle has been analyzed in order to get information on the mechanism of cell division. It was found that a decrease in recombinants and complementation events, which is expected at the time of cell compartmentalization coincides with physical cell separation. Therefore, we conclude that the two halves of a dividing cell remain connected until a very late stage of the division period, thus allowing exchange of DNA and protein molecules.

When a synchronized culture of E. coli B/r is infected at different cell age with phage T4, the number of surviving cells increases 10 min prior to cell division. At this time the cells are separated into two independent targets for killing by the phage, although there is still free exchange of DNA and proteins within the whole cell. The localized action of murein metabolizing enzymes at the site of subsequent cell division is likely to create a barriere within the cell envelope that prevents the propagation of the phage killing signal.