Cells form either long screws or portions of a turn. Volutin granules are usually present. Usually motile by means of a tuft of polar flagella (5 to 20) which may occur at one or both ends of the cells. Aerobic, growing well on ordinary culture media except for one saprophyte and the pathogenic species; these have not yet been cultivated. Usually found in fresh and salt water containing organic matter.
The type species is Spirillum undula (Müller) Ehrenberg.
Key to the species of genus Spirillum.
I. One micron or less in diameter.
- A. Volutin granules present.
- 1. Slow to rapid liquefaction of gelatin.
- a. Grayish to brown growth on potato.
1. Spirilluni undula.
- aa. Light yellowish orange growth on potato.
2. Spirillum serpens.
- 2. No liquefaction of gelatin. Of small size (0.5 micron in diameter).
- a. Colonies on agar white becoming brownish black and slightly wrinkled.
3. Spirillum itersonii.
- aa. Colonies on agar white and smooth.
4. Spirillum tenue.
- B. No volutin granules observed.
- 1. Single flagellum. From sea water.
5. Spirillum virginianum.
- 2. Tuft of flagella. From blood of rats and mice.
6. Spirillum minus.
II. Over 1 micron in diameter.
- A. Grow poorly or not at all on peptone agar media.
- 1. Grows poorly on peptone agar and potato.
7. Spirillum kutscheri.
- 2. Has not been cultivated on artificial media. Very evident volutin granules.
8. Spirillum volutans.
- B. Grows abundantly on peptone media. Cells may be deformed with fat droplets.
9. Spirillum lipoferum.
1. Spirillum undula (Müller, 1786) Ehrenberg, 1832. (Vibrio undula Müller, Animalcula infusoria et marina, 1786; Ehrenberg, Physik. Abhandlungen d. k. Berl. Akad., 1832, 38.) un'du.la. L. noun unda a wave; M.L. dim.fem.n. undula a small wave. Stout threads, 0.9 micron in diameter, with one-half to three turns. The wave lengths are 6 microns. Width of spiral, 3.0 microns. Tufts of three to nine flagella at each pole. Volutin granules present. Gram- negative. Gelatin colonies: The surface colonies are circular, granular, greenish yellow, entire. Gelatin stab: Thick, white, rugose sur- face growth. Very slow liquefaction. Agar colonies: Grayish white, smooth. Broth: Turbid. Potato: Grayish brown growth. Indole not produced. Catalase-positive. Nitrites not produced from nitrates, Aerobic, facultative. Optimum temperature, 25° C. Cohn (Beitrage z. Biol. d. Pflanzen, 1, Heft 2, 1875, 132) reports that he could not distinguish this organism from Vibrio prolifer Ehrenberg. Habitat: Putrid and stagnant water.
2. Spirillum serpens (Miiller, 1786) Winter, 1884. (Vibrio serpens Müller, Animalcula infusoria et marina, 1786, 43;
