Detection of fine spiral structures (spirosomes) by weak sonication in some bacterial strains

Fine spiral structures (spirosomes) were observed in cell suspensions of five species of bacteria just after weak sonication. The structure is morphologically indistinguishable from the spirosome reported for Lactobacillus species. The molecular weight of the protein of the spirosomes from nine strains was about 94,000 to 95,000 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The difference in the molecular weight among these spirosomes was not very great, but there were slight differences among the strains from which the spirosomes were derived.