Clostridium bifermentans
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster XI (non-Clostridium
sensu stricto),
Clostridium bifermentans  (Weinberg and Séguin 1918) Bergey, Harrison, Breed, Hammer and Huntoon 1923, emend.
Chamkha, Bharat, Garcia and Labat 2001.
Historical synonyms:
Bacillus bifermentans sporogenes Tissier and Martelly 1902,  Bacillus bifermentans  Weinberg and Séguin
Martellillus bifermentans  (Weinberg and Séguin) Heller 1922.
Gram-positive, straight rods, 0.6-1.9 x 1.6-11.0 µm, occur singly, in pairs or short
chains. Motile by peritrichous flagella. Spores are oval, central or subterminal, usually
not swelling the cell; sporulation occurs readily both in PY broth and on
chopped-meat agar slants. The composition of sporulation medium can affect their
germination rate and  resistance to heat and to chemical agents. Spores have an
exosporium. Six different types of spores have been identified depending on the
presence, type, or absence of spore appendages.
Surface colonies on blood agar plates are 0.5–4 mm in diameter, circular with irregular
margins, flat or raised, lobate or scalloped, translucent or opaque, granular or slightly
mottled, gray, shiny, and smooth. Individual colonies can often be seen best on 4%
agar plates. Most strains are beta-hemolytic. Beef liver catalase in plating media
increases growth. Cultures in PYG broth are turbid with a heavy, often ropy, sediment.
Good growth in nutrient broth, cooked meat broth, with viscid sediment.
Optimum growth at:  30-37 ºC and pH 7.0. Grow at 25 and 45 ºC. Growth is inhibited by 6.5% NaCl and by 20% bile. Abundant gas is
produced in PYG deep agar cultures. Major products of metabolism in PYG broth: acetic  acid, formic acid and abundant hydrogen.
Isolated from soil; fresh water; marine sediments; human feces; normal cervical flora; snake venom; a goat stomach ulcer; wounds in
horses and sheep; clinical specimens including wounds, abscesses, and blood; clam gut; cheese fondue; canned tomatoes and
vacuum packed smoked fish.
Susceptible to chloramphenicol, erythromycin, penicillin G.
Non-pathogenic for laboratory animals (mouse). Toxin is not produced.
  1. N.A. Logan and P. De Vos, 2009. Genus I. Clostridium Prazmowski 1880. In: (Eds.) P.D. Vos, G. Garrity, D. Jones, N.R. Krieg, W.
    Ludwig, F.A. Rainey, K.-H. Schleifer, W.B. Whitman. Bergey’s Manual of Systematic Bacteriology, Volume 3: The Firmicutes,
    Springer, 738-828.
  2. Smith L.D.S. and Hobbs G., 1975. Genus III. Clostridium Prazmowski 1880. In: (Eds.) Buchanan R.E. and Gibbons N.E., Bergey’s
    Manual of Determinative Bacteriology, Eighth Edition , The Williams & Wilkins Company, Baltimore, 551-572.
  3. Macovei A., 2009. Identificarea bacteriilor anaerobe. In: Tratat de Microbiologie Clinica (Ed. Buiuc D. si Negut M.), editia a IIIa,
    Editura Medicala, Bucuresti, 900-927.
H2 is produced in large amounts. Milk reaction is variable. Meat is digested.

Positive results for ammonia production, casein hydrolysis, gelatin hydrolysis, indole production, lecithinase, neutral red reduction,
substrate utilized and/or acid produced from glucose.

Negative results for lipase, starch hydrolysis, urease, Voges-Proskauer, substrate utilized and/or acid produced from: amygdalin,
arabinose, cellobiose, dulcitol, galactose, glycogen, inositol, inulin, lactose, mannitol,  melezitose, melibiose, raffinose, rhamnose,
ribose, salicin, sorbose, starch, sucrose, trehalose & xylose.

Variable results for esculin hydrolysis, H
2S production, hippurate hydrolysis, nitrate reduction, resazurin reduction, substrate utilized
and/or acid produced from: fructose, glycerol, maltose (weak), mannose (weak) & sorbitol (weak).
(c) Costin Stoica
Culture media
Biochemical tests
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