Abstract
The locality and the function of spirosome were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electron microscopy in Peptostreptococcus productus, Clostridium sp. HD-17, Lactobacillus fermentum, Eubacterium aerofaciens and Escherichia cali B. When the bacterial cells in phosphate buffered saline were disrupted by sonication and fractionated by differential centrifugation, the spirosome protein was found in the cytoplasmic fraction and not in the fraction of cell wall and cell membrane (the envelope fraction). The spirosome protein was found, however, in the envelope fraction when the bacterial cells were treated with a proper concentration of SDS. The spirosome protein in the envelope fraction disappeared after treatment with 2% Triton X-100 for 2h. These results suggest that the spirosome protein anchored to the cell membrane upon SDS treatment. So it is presumed that the locality of spirosome is close to the cell membrane. Spirosome production increased in parallel to the concentration of glucose in the medium in obligate and aerotolerant anaerobes as well as in facultative anaerobes. This result indicates that the spirosome production was induced during the process of anaerobic glycolysis. Fructose as the sole carbon source in the minimal medium induced the spirosome production by E. coli as did glucose, but sodium pyruvate did not induce it either under aerobic or anaerobic condition.
