Stimulation and inhibition of cell division in synchronized Escherichia coli.

Escherichia coli was synchronized by centrifugal elutriation. When grown in a Tris-based medium, addition of EDTA resulted in division about 20 min earlier (division of control at t = 75 min). EDTA addition caused a change in cell shape, with cells becoming narrower and longer, whereas the surface area to volume ratio increased. Irradiation with UV inhibited not only division and constriction, but also the increase in DAP incorporation found in dividing control cells. Possibly, division requires the construction of new polar caps, whereas premature division might involve remodeling of existing murein. In both cases, cell shape is presumed to be a relevant factor for division.