Page:Bergey's manual of determinative bacteriology.djvu/68

 Capable of photosynthesis in the presence of hydrogen sulfide, when the cells store elemental sulfur as droplets inside the cells.

The type species is Thiopolycoccus ruber Winogradsky.

1. Thiopolycoccus ruber Winogradsky, 1888. (Schwefelbacterien, Leipzig, 1888, 79.)

ru′ber. L. adj. ruber red.

Cells spherical, about 1.2 microns in diameter. No motility observed.

Habitat: Mud and stagnant water containing hydrogen sulfide and exposed to light; sulfur springs.

Illustrations: Winogradsky, ''loc. cit.'', Pl. IV, fig. 16-18; Issatchenko, Recherches sur les microbes de l'océan glacial arctique, Petrograd, 1914, Pl. II, fig. 7.

(Ophidomonas Ehrenberg, Die Infusionstierchen, Leipzig, 1838, 43; Winogradsky, Schwefelbacterien, Leipzig, 1888, 104.)

Thi.o.spi.ril′lum. Gr. noun thium sulfur; M.L. dim. neut. n. Spirillum a bacterial genus; Gr. noun spira a spiral; M.L. neut.n. Thiospirillum sulfur Spirillum.

Sulfur purple bacteria, occurring singly as spirally wound cells, motile by means of polar flagella. Contain bacteriochlorophyll and carotenoid pigments, coloring the cells brownish to purplish red. Capable of photosynthesis in the presence of hydrogen sulfide, during which they produce and store, as an intermediate oxidation product, elemental sulfur in the form of droplets inside the cells.

The differentiation of species in this group has been based exclusively on observations with material from natural collections and from laboratory mass cultures. The criteria used are the size and shape of the spirals and the color of the organisms. Not a single representative has so far been obtained and studied in pure culture, so that no information is available concerning the constancy or variability of these characteristics. It is likely, however, that such properties may be greatly influenced by environmental factors. Hence, the following key and descriptions of species are apt to be modified when more extensive studies have been made. The published descriptions of some species make it seem probable that they should not even be incorporated in Thiospirillum.

The type species is Thiospirillum jenense (Ehrenberg) Winogradsky.

I. Width of cells 2.5 microns or more.


 * A. Color of cells, especially in masses, yellowish brown to orange-brown.


 * B. Color of cells deep red or violet.
 * 1. Cells long, typical spirals; clearly red.


 * 2. Cells short, slightly curved, vibrio-shaped; color purple to violet-red.

II. Width of cells less than 2.5 microns.


 * A. Width of cells 1.5 to 2.5 microns.


 * B. Width of cells about 1 micron.

1. Thiospirillum jenense (Ehrenberg, 1838) Winogradsky, 1888. (Ophidomonas jenensis Ehrenberg, Die Infusionstierchen, Leipzig, 1838, 44; Winogradsky, Schwefelbacterien, Leipzig, 1888, 104; Thiospirillum crassum Hama, Jour. Sci. Hiroshima Univ., Ser. B, Div. 2, Bot., 1, 1933, 157.)

je.nen′se. M.L. adj. jenensis pertaining to