Cultural characteristics
Biochemical characters
Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster XI (Clostridium non
sensu stricto),
Clostridium glycolicum Gaston and Stadtman 1963, emend. Chamkha, Labat, Patel and Garcia 2001.
Gram-positive, straight to slightly curved rods, 0.3-1.3 x 1.8-15.4 µm, occuring singly or in pairs. Motile by peritrichous flagella. Spores
are oval, subterminal/terminal, non-swelling, often occurring as free spores; sporulation occurs most readily in chopped-meat broth
cultures or on chopped-meat agar slants.
Surface colonies on blood agar plates are 1–4 mm in diameter, circular to irregular,
translucent to opaque, raised to convex, grayish white, shiny, and smooth with a
granular, mottled or mosaic internal structure, and entire, scalloped or erose margins.
Cultures in PYG broth are turbid with a smooth to stringy sediment and have a pH of
5.5–5.9 after incubation for 24 hours and a pH of 5.2-5.6 after 5 days. Moderate growth
in nutrient broth without fermentable carbohydrate; profuse growth with fermentable
carbohydrate. Abundant gas is produced in PYG deep agar cultures. Strictly anaerobic.
Growth is inhibited by
6.5% NaCl, 20% bile and a pH of 9.5. Optimum temperature for
growth is 30-37 ºC. Can grow at 25 ºC. Weak, variable growth at 45 ºC. No growth at 10
ºC. Optimum pH 7.3-7.5; range 6.0-9.4. Ferment ethylene glycol to acetate and ethanol,
and propylene glycol to propionate, propanol, and small amounts of acetate and
ethanol. Major products of metabolism in PYG broth: acetic, isovaleric, and isobutyric
acids, and ethyl, propyl, isobutyl, isoamyl alcohols, and abundant amounts of hydrogen.
Isolated from soil, mud, olive mill wastewater, snake venom, bovine intestine; human clinical specimens including wounds,
abscesses, and peritoneal fluid; human feces. Susceptible to penicillin G.
Nonpathogenic for laboratory animals. Toxin is not produced. Isolated from human clinical specimens including wounds, abscesses,
and peritoneal fluid.
  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., 1974. 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. Chamkha M., Labat M., Patel B.K.C. and Garcia J.L., 2001. Isolation of a cinnamic acid-metabolizing Clostridium glycolicum strain
    from oil mill wastewaters and emendation of the species description. IJSEM 51, 2049-2054.
Milk reaction is negative. The production of large amounts of isovaleric acid is most helpful in distinguishing this species from other
saccharolytic, nonproteolytic clostridia.

Positive results for H
2 production (abundantly), ammonia production, casein hydrolysis, DNase, substrate utilized and/or acid
produced from: fructose, glucose, sorbitol & xylose.

Negative results for gelatin hydrolysis, indole production, lecithinase, lipase, nitrate reduction, starch hydrolysis, Voges - Proskauer
test, substrate utilized and/or acid produced from: amygdalin, adonitol, arabinose, cellobiose, cellulose, esculin, erythritol, galactose,
glycogen, glycerol, inositol, inulin, lactose, mannitol, mannose, melezitose, melibiose, raffinose, rhamnose, ribose, salicin, sorbose,
starch, sucrose & trehalose.

Variable results for H
2S production, hippurate hydrolysis, substrate utilized and/or acid produced from: dulcitol & maltose.
Clostridium glycolicum
(c) Costin Stoica
Culture media
Biochemical tests
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