Page:Bergey's manual of determinative bacteriology.djvu/99

 4. Hydrogenomonas vitrea Niklewski, 1910. (Jahrb. f. wissensch. Botanik, 48, 1910, 113.)

vit′re.a. L. vitreus of glass.

Rods 2.0 microns in length, cells adhering to each other as by slime. Motility not observed.

Agar colonies on inorganic medium in presence of H2, O2 and CO2: Delicate, transparent, with slight fluorescence and yellow center. Surface folded. Do not develop readily beneath the surface of medium.

Agar streak on inorganic substrate: Same as agar colonies except that growth is spreading.

Inorganic liquid medium in presence of H2, O2 and CO2: Pellicle, adherent to wall of tube. Good development when there is from 2 to 8 per cent oxygen in the gas. At higher O2 concentrations good growth occurs only in association with H. flava or other bacteria.

Oxidizes hydrogen to water.

Microaerophilic, growing in an atmosphere of low oxygen tension, not exceeding 8 per cent.

Facultatively autotrophic.

Distinctive characters: Grows in substrates containing no organic matter and produces a pellicle.

Source: Isolated from mud, garden soil, pasture land, vegetable mold and peat.

Habitat: Presumably widely distributed in soil.

Car.box.y.do.mo′nas. L. noun carbo charcoal, carbon; Gr. adj. oxys sharp; Gr. noun monas a unit, monad; M.L. fem. n. Carboxydomonas the carbon-oxidizing monad.

Autotrophic, rod-shaped cells capable of securing growth energy by the oxidation of CO, forming CO2.

The type species is Carboxydomonas oligocarbophila (Beijerinck and van Delden) Orla-Jensen.

1. Carboxydomonas oligocarbophila (Beijerinck and van Delden, 1903) Orla-Jensen, 1909. (Bacillus oligocarbophilus Beijerinck and van Delden, Cent. f. Bakt., II Abt., 10, 1903, 33; Orla-Jensen, Cent. f. Bakt., II Abt., 22, 1909, 311.)

o.li.go.car.bo′phi.la. Gr. adj. oligus little, scanty; L. noun carbo charcoal, carbon; Gr. adj. philus loving; M.L. adj. oligocarbophilus loving little carbon.

Rods very small, 0.5 by 1.0 micron, colorless, united into irregular masses by a slimy substance. Non-motile. There is little cytoplasm within the slimy, cellulose-like wall of the cells.

Growth occurs in culture fluids free from organic matter and on washed agar containing the necessary inorganic salts.

Media containing carbonaceous materials: No growth.

Liquid media: A thick, slimy film is produced.

CO is utilized as food and as such is oxidized to CO2. In symbiosis with other bacteria, hydrogen in water is oxidized by the catalytic reduction of CO2 to CO. The CO is then metabolized, again forming CO2 (Kaserer. Cent. f. Bakt., II Abt., 16, 1906, 681).

Growth best in the dark.

Optimum temperature, 25° C.