Page:Bergey's manual of determinative bacteriology.djvu/272



Me.tha.no.bac.te'ri.um. Gr. noun methy wine; M.L. noun methanum methane; Gr. neut.n. bacterium a small rod; M.L. noun Methanobacterium the methane (-producing) rodlet.

Straight or slightly curved rods, sometimes united in bundles or long chains. Reported to be non-motile. Anaerobic. Chemo-heterotrophic or chemo-autotrophic, oxidizing various organic or inorganic compounds and reducing carbon dioxide to methane. Gram-negative.

The anaerobic genus Methanobacterium was proposed by Kluyver and van Niel in 1936 with an indication that they regarded Söhngen's methane bacterium as the type species of the genus. Later, Barker (1936) found organisms that he regarded as identical with those previously isolated by Söhngen, and he proposed the name Methanobacterium söhngenii for this species. While the organisms belonging to this genus are reported to be non-motile, the curved form of their cells and their physiology places them near the species placed in Desulfovibrio.

The type species is Methanobacterium soehngenii Barker.

1. Methanobacterium soehngenii Acetate and n-butyrate but not pro- Barker, 1936. (Methane bacterium, Sohn- pionate are fermented with the production gen, Dissertation, Delft, 1906; Barker, Arch. of methane and carbon dioxide, f. Mikrobiol., 7, 1936, 433.) Ethyl and n-butyl alcohols not fermented. soehn.ge'ni.i. M.L. gen.noun soehngenii Obligate anaerobe, of Sohngen; named for Prof. N. L. Sohngen, g^^^.^^. Enrichment cultures containing the bacteriologist who first studied this acetate or butyrate as the only organic com- ?,,■., ,., , , , pound. Four strains were isolated from ace- Rods straight to slightly curved, moder- "■' . . ^ ,^ rr,, ,., ^, , ,, ,., ^, ,. tate enrichment cultures. The cultures were ately long. ISon-motile. Gram-negative. .^ , , . , In liquid cultures, cells are character- highly purified but not strictly pure, istically joined into long chains which often Habitat: Canal mud, sewage. Probably lie parallel to one another so as to form occurs widely in fresh-water sediments bundles. where anaerobic conditions prevail.

Cell.vib'ri.o. L. noun cella a room, cell; L. v. vibro to vibrate; M.L. mas.n. Vibrio that which vibrates, a generic name; M.L. mas.n. Cellvibrio cell vibrio, but here the cell is an abbreviation of cellulose, hence, cellulose vibrio.

Long slender rods, slightly curved, with rounded ends, showing deeply staining granules which appear to be concerned in reproduction. Monotrichous. Most species produce a yellow or brown pigment with cellulose. Oxidize cellulose, forming oxycellulose. Growth on ordinary culture media is feeble. Found in soil.

The type species is Cellvibrio ochraceus Winogradsky.

I. No growth on glucose or starch agar.
 * A. Ochre-yellow pigment produced on filter paper.