Abstract
Rhapidosomes were demonstrated by electron microscopy to be present abundantly in the autolysate of two strains belonging to the B type of Clostridium botulinum. They were revealed as hollow cylinders with rather round tips, which were 280 to 400 in diameter and varied in length, regardless of the strains. The time lapse observations of autolytic process suggested that the rhapidosomes were produced by the original disintegration of membranous structures such as the cytoplasmic membrane and the mesosomes to turn into rod bodies, and by final liberation into the autolysates. The purified rhapidosomes were found to be composed of 62.5% protein, 32.0% lipid, and 1.7% ribonucleic acid, without detection of deoxyribonucleic acid or carbohydrates. The rhapidosomes were toxic to mice, 50% lethal dose being about 1μg of their protein.
When actively growing cells of both strains were treated with Mitomycin- C or ultraviolet ray, several kinds of phages or phage component-like structures were found. The morphological characteristics of these structures were described, and proved not to resemble the rhapidosomes.
