Page:Bergey's manual of determinative bacteriology.djvu/206

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184
ORDER I. PSEUDOMONADALES

Thesis, Leiden, 1898, 115 pp.. Delft, in Cent. f. Bakt., II Abt., 4, 1898, 857; Acetobacter Beijerinck, Proc. Kon. Akad. v. Wetenschapp., Amsterdam, 2, 1900, 503; Acetobacter Beijerinck. Arch, néerl. d. sciences exact. et natur., Sér. II, 6, 1901, 212; Acetobacter in Fuhrmann, Beiheft Bot. Centralbl., Orig., 19, 1905, 8; Acetimonas Orla-Jensen, Cent. f. Bakt., II Abt., 22, 1909, 312; Acetobacter Winslow et al.. Jour. Bact., 5, 1920, 201; Acetomonas Leifson, Antonie van Leeuwenhoek, 20, 1954, 109.)

A.ce.to.bac'ter. L. noun acetum vinegar; M.L. mas.n. bacter the masculine form of the Gr. neut.n. bactrum a rod or staff; M.L. mas.n. Acetobacter vinegar (acetic) rod.

Individual cells ellipsoidal to rod-shaped, occurring singly, in pairs or in short or long chains. Motile with polar flagella[1], or non-motile. Involution forms may be spherical, elongated, filamentous, club-shaped, swollen, curved or may even appear to be branched. Young cells Gram-negative; old cells often Gram- variable. Obligate aerobes; as a rule strongly catalase-positive, sometimes weakly so. Oxidize various organic compounds to organic acids and other oxidation products which may undergo further oxidation. Common oxidation products include acetic acid from ethyl alcohol, gluconic and 5-ketogluconic acid from glucose, dihydroxy-acetone from glycerol, sorbose from sorbitol, etc. Nutritional requirements vary from simple to complex. Development generally best in yeast infusion or yeast autolysate media with added ethyl alcohol or other o.xidizable substrates. Optimum temperature varies with the species. Widely distributed in nature where they are particularly abundant in plant materials undergoing alcoholic fermentation; of importance to man for their role in the completion of the carbon cycle and for the production of vinegar.

It is recognized that there are marked morphological and physiological similarities between species of Acetobacter and Pseudomonas (see Vaughn, Jour. Bact., 46, 1943, 394; and Stanier, Jour. Bact., 54, 1947, 191, among others). However, the species of Acetobacter may be differentiated from all other Pseudomonadaceae by their unique ability to oxidize significant quantities of ethanol under the extremely acidic conditions imposed by the presence of from about 2 to more than 11 per cent acetic acid.

The evidence also indicates a significant difference in the end-products of hexose and disaccharide oxidation. The species of Acetobacter produce gluconic and 5-ketogluconic acids from both glucose and maltose whereas species of Pseudomonas oxidize glucose to gluconic and 2-ketogluconic acids and maltose to maltobionic acid (see Pervozvanski, Khim. Referat. Zhur., 7, 1939, 43; Lockwood, Tabenkin and Ward, Jour. Bact., 42, 1941, 51; Stodola and Lockwood, Jour. Biol. Chem., 171, 1947, 213; Kluyver, Deley and Rijven, Antonie van Leeuwenhoek, 16, 1950, 1; and Foda and Vaughn, Jour. Bact., 65, 1953, 233, among others).

The type species is Acetobacter aceti (Beijerinck) Beijerinck.

Key to the species of genus Acetobacter.

I. Oxidize acetic acid to carbon dioxide and water.

A. Utilizes ammonium salts as a sole source of nitrogen (Hoyer's solution).[2]

1. Acetobacter aceti.

  1. Leifson (Bact. Proc, 53rd Gen. Meeting Soc. Amer. Bact., 1953, 34, and Antonie van Leeuwenhoek, 20, 1954, 102), in a study of the flagellation of cultures of Acetobacter, reports that the species of Acetobacter that oxidize acetic acid are peritrichous, and that the species that do not oxidize acetic acid ordinarily have four polar flagella. Further photographs such as can be obtained with the electron microscope must, however, be obtained before the exact point of attachment of the flagella can be determined with certainty.
  2. It is not known with certainty whether Acetobacter pasteurianus and Acetobacter kuetzingianus are capable of using inorganic nitrogen as a sole source of nitrogen for growth. See Acetobacter rancens Beijerinck to which these two species are very closely related. Also see Frateur, La Cellule, 53, 1950, 316-320.
    Species Nos. 2 to 3b inclusive will, however, utilize ammonium salts if supplied with