Effects of calcium and calcium chelators on growth and morphology of Escherichia coli L-form NC-7.

Growth of a wall-less, L-form of Escherichia coli specifically requires calcium, and in its absence, cells ceased dividing, became spherical, swelled, developed large vacuoles, and eventually lysed. The key cell division protein, FtsZ, was present in the L-form at a concentration five times less than that in the parental strain. One interpretation of these results is that the L-form possesses an enzoskeleton partly regulated by calcium.