Page:Bergey's manual of determinative bacteriology.djvu/62

 carotenoid pigments, hence, pigmented purplish to red. Capable of carrying out a photosynthetic metabolism in the presence of hydrogen sulfide, cells then storing sulfur globules. Anaerobic.

The type species is Thiosarcina rosea (Schroeter) Winogradsky.

1. Thiosarcina rosea (Schroeter, 1886) Winogradsky, 1888. (Sarcina rosea Schroeter, Kryptog.-Flora von Schlesien, 3, 1, 1886, 154; Winogradsky, Zur Morphologie und Physiologic der Schwefelbacterien, Leipzig, 1888, 104.)

ro′se.a. L. adj. roseus rosy, rose-colored.

Cells spherical, 2 to 3 microns in diameter, occurring in packets containing 8 to 64 cells. Infrequently motile. Color ranging from purplish rose to nearly black.

Anaerobic.

Habitat: Occur less frequently than other sulfur purple bacteria; probably widely distributed in mud and stagnant bodies of water containing hydrogen sulfide and exposed to light; sulfur springs.

Illustration: Issatchenko, Recherches sur les microbes de l'océan glacial arctique, Petrograd, 1914, Plate II, fig. 5.

(Zur Morphologie und Physiologie der Bacterien, I. Schwefelbacterien, Leipzig, 1888, 85.)

Thi.o.pe′di.a. Gr. n. thium sulfur; Gr. n. pedium a plain, a flat area; M.L. fem. n. Thiopedia a sulfur plain.

Individual cells spherical to short rod-shaped, the latter shortly before cell division. Arranged in flat sheets with typical tetrads as the structural units. These arise from divisions of the cells in two perpendicular directions. Cell aggregates of various sizes, ranging from single tetrads to large sheets composed of thousands of cells. Non-motile. Non-spore-forming. Contain bacteriochlorophyll and carotenoid pigments. Capable of photosynthesis in the presence of hydrogen sulfide, then storing sulfur globules. Anaerobic.

The type species is Thiopedia rosea Winogradsky.

1. Thiopedia rosea Winogradsky, 1888. (Erythroconis littoralis Oersted, Naturhist. Tidsskrift, 3, 1840-1841, 555; Winogradsky, Zur Morphologie und Physiologie der Schwefelbacterien, Leipzig, 1888, 85.)

ro′se.a. L. adj. roseus rosy, rose-colored.

Cells 1 to 2 microns, often appearing as slightly elongated cocci regularly arranged in platelets.

Color, pale red to nearly black, depending upon the amount of sulfur stored. Red color visible only with large cell masses, not in individuals.

According to Winogradsky, the cells are often embedded in a common slime capsule; the extensive studies of Utermöhl (Archiv f. Hydrobiol., Suppl. Vol. 5, 1925, 251-276) make the regular occurrence of such capsules extremely doubtful. On the other hand, Utermöhl emphasizes as quite characteristic the common presence of a relatively large pseudovacuole, or aerosome, in the cells of this species encountered in plankton samples. Winogradsky does not mention this; nevertheless, it appears to be a regular and valuable distinguishing feature.

Anaerobic.

Habitat: Widely distributed in mud and stagnant bodies of fresh, brackish and salt water containing hydrogen sulfide and exposed to light; sulfur springs. Common, frequently giving rise to very extensive mass developments.

Illustrations: Warming, Videnskab. Meddel. naturhist. Forening, Kjöbenhavn, 1876, Plate VIII, fig. 2; Winogradsky, op. cit., 1888, 85, Plate III, fig. 18; Pringsheim, Naturwissensch., 20, 1932, 481, the last one a truly excellent photomicrograph.