Remarkably, growth of L. plantarum in the presence of 8% ethanol resulted in invaginating spirals at the septum site of dividing cells. This phenotype resembles that of a conditional ftsZ mutant of Escherichia coli when it was grown at nonpermissive growth temperatures. The division defect of the E. coli ftsZ mutant was explained by a failure in FtsZ-ring assembly and closure (1, 5).