width 4 to 5 microns. Slightly attenuated ends. Dark granules of volutin are present in the cytoplasm. Motile, possessing a tuft of ten to fifteen fiagella at each pole. Gram- negative. Migula (Syst. d. Bakt., 2, 1900, 1025) reports that this species has not been cultivated on artificial media and that the cultures described by Kutscher (Ztschr. f. Hyg., 20, 1895, 58) as Spirillum volutans are of a different species. Vahle (Cent. f. Hakt., II Abt., 25, 1910, 237) later describes the cultural characters of an organism which he regards as identical with Kutscher's organism. Giesberger (Inaug. Diss., Delft, 1936, 65) saw what he felt was the true Spirillum volutans but could not cultivate it. Optimum temperature, 35° C. Habitat: Stagnant water.
9. Spirillum lipoferum Beijerinck, 1925. (Azotobacier spirillum Beijerinck, Kon. Akad. Wetensch. Amsterdam, 30, 1923, 431, ([uoted from Giesberger, Inaug. Diss., Delft., 1936, 24; Beijerinck, Cent. f. Bakt., II Abt., 63, 1925, 353.) li.po'fe.rum. Gr. noun lipus fat; L. v.fero to carry; M.L. adj. lipoferus fat-bearing. Curved cells with one-half to one spiral turn. Contain minute fat droplets which ma}^ deform the cells. Motile by means of a tuft of polar fiagella. Gram-negative. Calcium malate agar colonies: Circular, small, transparent, dry. The malate is oxi- dized to calcium carbonate. Cells contain fat droplets. Peptone agar colonies: More abundant development. Cells lack fat droplets and are typically spirillum in form. Glucose peptone broth: Cells actively motile with large fat droplets. Fixes atmospheric nitrogen in partially pure cultures, i.e., free from Azotobacter and Clostridium (Beijerinck, loc. cit.). Schroder (Cent. f. Bakt., II Abt., 85, 1932, 17) failed to find fixation of nitrogen when she used cultures derived from a single cell. Aerobic. Optimum temperature, 22° C. Beijerinck regards this as a transitional form between Spirillum and Azotobacter. Giesberger (op. cit., 1936, 64) thinks it a Vibrio. Habitat: Garden soil.
Genus VIII. Paraspirillum Dobell, 1912.[1]
(Arch. f. Protistenk., 24, 1912, 97.)
Pa.ra.spi.ril'lum. Gr. pref. para beside; M.L. neut.n. Spirillum a genus of bacteria; M.L. neut.n. Paraspirillum Spirillum-like (organisms).
Cells spiral or S-shaped, tapering toward the ends, with a well marked thickening toward the middle of the body; resemble much elongated and spirally twisted spindles. Motile by means of a single, polar flagellum. Found in fresh water.
Dobell (loc. cit.) believes that this organism belongs to the Spirillaceae rather than to the Spirochaetaceae.
The type species is Paraspirillum vejdovskii Dobell.
1. Paraspirillum vejdovskii Dobell, 1912. (Arch. f. Protistenk., 24, 1912, 97.) vej .dov'ski.i. M.L. gen. noun vejdovskii of Vejdovsky; named for Prof. F. Vejdovsky. Spiral or S-shaped rods, tapering toward the ends, 8 to 25 microns in length, averag- ing 15 microns. Width, in the middle, 1.5 to to 2.0 microns. A definite spherical to ellip- soidal nucleus is present. The cytoplasm immediately about the nucleus is hyaline or very finely granular. Volutin granules are numerous between the hyaline area and the ends of the cell. Locomotion is screw- like, resembling that characteristic of spe- cies of Spirillum. The motion is reversible, and cells may swim in either direction. In motion the cell seems to be rigid, but it may increase or decrease the amount of bending. Sometimes the cell is much-curved, at other
- ↑ Prepared by Prof. R. E. Buchanan, Iowa State College, Ames, Iowa, July, 1952.
