Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster III (non-Clostridium
sensu stricto), Clostridium cellobioparum Hungate 1944.
Gram-negative, straight or slightly curved rods, 0.5-0.6 x 1.4-3.3 µm, occur singly or in
pairs . Motile by peritrichous flagella. Spores are sphaerical/oval, terminal, swelling
the cell; sporulation occurs most readily on cellulose agar or in 3-week-old rumen
fluid broth cultures.
Surface colonies on blood agar plates are 0.5-1.5 mm in diameter, convex to pulvinate,
semiopaque, creamy white to yellowish, shiny, and smooth. On rumen fluid cellobiose
agar, they may have a scalloped margin, raised elevation, and translucent appearance.
Cultures in PYG broth supplemented with rumen fluid are turbid with a stringy sediment
and have a pH of 5.3-5.5 after incubation for 5 days. Slight growth in nutrient broth
without fermentable carbohydrate; profuse growth with fermentable carbohydrate.
Ropy sediment. Growth is stimulated by rumen fluid, a fermentable carbohydrate, and
a gaseous atmosphere of 90% N2 and 10% CO2.
Hydrogen produced by this organism will limit growth unless removed either mechanically or by H2-utilizing organisms growing
concurrently. No aerotolerance. Grows optimally at 30-37 ºC and pH 7.0. Variable growth at 25 ºC. No growt at 45 ºC.
Isolated from the bovine rumen, human feces. The type strain is susceptible to chloramphenicol, clindamycin, erythromycin, penicillin
G, and tetracycline.
Nonpathogenic for laboratory animals. Toxin is not produced. Blood is not hemolyzed.
- 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,
- 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.
Fermentation products in PYG broth are acetic, lactic, and formic acids, ethanol, CO2, and H2. Cellulose is hydrolyzed to cellobiose.
H2 is produced very abundantly. Milk reaction and meat digestion are negative.
Positive results for esculin hydrolysis, substrate utilized and/or acid produced from: arabinose, cellobiose, cellulose, dulcitol, fructose,
galactose, glucose, glycerol (weak), lactose (weak), maltose, mannose, melibiose, ribose, salicin (weak) & xylose.
Negative results for casein hydrolysis, catalase, gelatin hydrolysis, H2S production, indole production, lecithinase, lipase, neutral red
reduction, nitrate reduction, resazurin reduction, starch hydrolysis, urease, substrate utilized and/or acid produced from: adonitol,
amygdalin, erythritol, glycogen, inositol, inulin, mannitol, melezitose, raffinose, rhamnose, sorbitol, sorbose, starch. sucrose &
Variable results for Voges-Proskauer test.
(c) Costin Stoica