Page:Bergey's manual of determinative bacteriology.djvu/228

 Gelatin stab: Saccate liquefaction. Agar colonies: Circular, white, convex, smooth, glistening, entire. Agar slant: Filiform, white, convex, smooth, glistening, entire. Broth: Turbid. Nitrites not produced from nitrates. Gas, presumably N2, in fermentation tubes. Starch not hydrolyzed. No acid from carbohydrate media. Attacks phenol. Aerobic. Optimum temperature, below 30°C. Source: Two strains isolated from soil. Habitat: Probably widely distributed in soil. Possibly also found in marine habitats. Note: Species incertae sedis. Other bac- teria from sea water, fresh water and soil have been described as belonging in this genus. Their relationships to the species described by Gray and Thornton (Cent, f. Bakt., II Abt., 73, 1928, 82) have not yet been definitely established.

Zo.o.gloe'a. Gr. adj. zous living; Gr. gloea glue; M.L. fem.n. Zoogloea living glue.

Rod-shaped cells embedded in a gelatinous matrix. Free-floating forms found in fresh water that contains organic matter. Occur as compact masses or as branched forms. Cells may become detached and motile in which case they are monotrichous.

The original description of this genus follows:

Zoogloea. Cellulae minimae bacilliformes hyalinae, gelatina hyalina in massas globosas, uvaeformes, mox membranaceae consociatae, dein singulae elapsae, per aquam vacillantes.

This may be freely translated as follows:

Zoogloea. Transparent, very small, rod-shaped cells embedded in transparent, gelatinous, clustered, spherical masses. Afterwards become detached as individuals swimming to and fro in the water.

Zoogloea termo Cohn, 1854, the type species (monotypy) of this genus, is generally thought to be unrecognizable. While awaiting further study of this problem by modern methods, it is recommended that Zoogloea ramigera Itzigsohn be accepted as the type species of Zoogloea Cohn.

1. Zoogloea ramigera Itzigsohn, 1867, emend. Bloch, 1918. (Itzigsohn, Sitzungsber. d. Gesellschaft naturf. Freunde, Berlin, Nov. 19, 1867, 30; Bloch, Cent. f. Bakt., II Abt., 48, 1918, 44-62.) ra.mi'ge.ra. L. ramus a branch; L. v. gero to bear; M.L. adj. ramigerus branch-bearing. Description taken from Bloch (loc. cit.), who made the first cultural studies of this species, Butterfield (Public Health Reports, 50, 1935, 671) and Wattie (Pub. Health Re- ports, 57, 1942, 1519). Rods, 1 by 2 to 4 microns, with rounded ends. Numerous cells are found embedded in a gelatinous, branching matrix (see Koch, Beitrage z. Biol. d. Pflanzen, 2, Heft 8, 1877, 399, Taf. XIV, and Butterfield, op. cit., 1935, plates I-IV). Free cells are motile with a single, long, polar flagellum. Gram-nega- tive. Bloch reports no growth at 25° C. on gela- tin, poor growth on nutrient agar, good growth in nutrient broth, weak growth in peptone water, very good growth in hay in- fusions, good growth in yeast extract water, no growth in liquid manure, no growth in beer wort, no growth on potato and no growth on yellow sugar beet. Butterfield re- ports that growth is best in aerated liquid media. Nitrites not produced from nitrates. Ammonia produced from peptones. Indole not produced. Hydrogen sulfide not produced. Methyl red negative; acetylmethylcar- binol not produced.