The relative rotation of the ends of Bacillus subtilis during growth.

Observation of long single filaments of Bacillus subtilis 168 in depression slide cultures demonstrated that one end rotated relative to the other during growth. This was observed with suspended filaments, filaments attached to glass surfaces and single stranded filaments folded back on themselves growing as a double stranded helix. This extends Mendelson's 1976 conclusion to cases with no alternative interpretation to the hypothesis that as each cell grows, the structure of the peptidoglycan changes to rotate one end relative to the other.