Clostridium butyricum
Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster I (Clostridium sensu
Clostridium butyricum Prazmowski 1880. Type species of the genus.
Historical synonyms:
Bacillus amylobacter van Tieghem 1877, Metallacter amylobacter (van Tieghem) Trevsan 1879, Bacterium
Reinke and Berthold 1879, Bacillus butyricus (Prazmowski) Flügge 1886, Bacillus navicula (Reinke and Berthold) Chester
Amylobacter navicula  (Reinke and Berthold) Wehmer 1898, Clostridium naviculum (Reinke and Berthold) Prevot 1938.
Clostridium pseudotetanicum” appears to be a later synonym of Clostridium butyricum, pending confirmation by DNA–DNA
homology determinations.
Gram-positive (Gram-negative in old cultures) straight or slightly curved rods, 0.5-1.7 x
2.4-7.6 µm,  with rounded ends; occur singly, in pairs, or in short chains, occasionally
as long filaments. Motile by peritrichous flagella. Spores are oval, central/subterminal,
usually do not swell the cell. Sporulation occurs readily both in broth and on solid
Growth on nutrient agar  or cooked meat broth is weak or negative. Grows on glucose
agar: Colonies are 1-3 mm in diameter, white to cream colour, glossy to matt surface.
On blood-agar colonies are 1-6 mm in diameter, circular to irregular, raised to convex,  
translucent, gray-white,  shiny or dull, smooth, with a granular or mottled internal
structure. Nonhemolytic.
Grows in broth media with a fermentable carbohydrate added with gas production.
Cultures in PYG broth (peptone yeast extract containing glucose) are turbid with a
smooth or flocculent sediment and have pH 4.6-5.0 after 5 days of incubation.
Growth is stimulated by a fermentable carbohydrate. No growth in 6.5% NaCl medium. Growth is readily in glucose-mineral salts
medium with biotin as the only required  vitamin. So, does not require amino acids or vitamins , other than biotin, for growth.
Optimum growth temperature 25-37 ºC. Growth at 10 ºC is variable.
Pectin degradation has been implicated in the formation of wetwood in living hardwood trees and in the anaerobic digestion of fruit
and vegetable wastes, and strains of
Clostridium butyricum which carry out these processes have been isolated from these sources.
Chlorinated hydrocarbon pesticides can be degraded in the presence of glucose by strains of this species.
Susceptible to clindamycin, chloramphenicol, erythromycin, and tetracycline.
A bacteriocin produced by the type strain is active against cell membrane functions of several species of clostridia, particularly those
Clostridium pasteurianum.
Source of isolation: soil, freshwater and marine sediments, cheese, naturally soured milk, rumen of healthy calves, animal & human
feces (including feces of healthy infants), snake venom, and, although seldom in pure culture, from a wide variety of human & animal
clinical specimens including those from blood, urine, lower respiratory tract, pleural cavity, abdomen, wounds, and abscesses.
Culture supernatants are not toxic to mice. Toxin is not produced. Not pathogenic for laboratory animals.
Isolated seldom in pure culture, from a wide variety of human and animal clinical specimens including those from blood, urine, lower
respiratory tract, pleural cavity, abdomen, wounds, and abscesses.
  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.
Products in PYG broth are butyric, acetic, and formic acids. H2 produced very abundantly. Milk reaction: curd. Meat is not digested.

Positive results for esculin hydrolysis, starch hydrolysis, N
2 atmospheric fixation, neutral red reduction, resazurin reduction, substrate
utilized and/or acid produced from:  cellobiose , fructose, galactose, glucose, glycogen, lactose, maltose, mannose, melibiose,
raffinose, ribose, salicin, starch, sucrose, trehalose & xylose. Pectin is strongly fermented.

Negative results for indole production, lecithinase, lipase, DN-ase, hydrolysis of casein, hydrolysis of gelatin, H
2S production, urease,
Voges-Proskauer reaction, substrate utilized and/or acid produced from: dulcitol, rhamnose, sorbitol & sorbose.

Variable results for nitrate reduction, substrate utilized and/or acid produced from: arabinose, amygdalin, esculin, glycerol,  inulin,
mannitol & melezitose.
(c) Costin Stoica
Culture media
Biochemical tests
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