Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster IV (non-Clostridium
sensu stricto), Clostridium sporosphaeroides Soriano and Soriano 1948.
Gram-positive, straight rods, 0.5-0.6 x 1.8-8.0 µm, occur singly, in pairs or chains.
Nonmotile. Spores are oval or round, terminally located. Sporulation occurs most
readily on chopped-meat slants incubated at 30 ºC. The cell wall is susceptible to
dissolution by lysozyme.
Colonies on the surface of blood agar are 1-2 mm in diameter, circular, with a slightly
lobate or scalloped margin, slightly raised, with a fried-egg appearance, gray-white,
have a glossy surface, a mosaic internal structure, and are nonhemolytic. No
Cultures in PYG broth are turbid with a smooth to ropy sediment and have a pH of 6.1
after incubation for 5 days. Poor to moderate growth in nutrient broth , cooked meat
broth, with a ropy sediment.
Optimum temperature for growth is 37-45 ºC. No growth at 25 ºC. Weak growth at 30
ºC. Growth is inhibited by 20% bile and by 6.5% NaCl.
A moderate amount of gas is produced in PYG deep agar cultures. Products of
metabolism in PYG broth include large amounts of acetate and butyrate. Abundant
hydrogen is produced.
Isolated from canned food and human feces.
Susceptible to chloramphenicol, clindamycin, erythromycin, penicillin G, and tetracycline.
Culture supernatants are not toxic for mice. Toxin is not produced.
- 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., 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.
Milk reaction (curd) is negative.
Positive results for ammonia production, H2S production, hippurate hydrolysis, neutral red reduction & resazurin reduction.
Negative results for DNase, casein hydrolysis, esculin hydrolysis, gelatin hydrolysis, indole production, lecithinase, lipase, nitrate
reduction, starch hydrolysis, urease, Voges-Proskauer reaction, substrate utilization and/or acid production from: adonitol, amygdalin,
arabinose, cellobiose, cellulose, dulcitol, erythritol, fructose, galactose, glucose, glycogen, glycerol, inositol, inulin, lactose, maltose,
mannitol, mannose, melezitose, melibiose, raffinose, rhamnose, ribose, salicin, sorbitol, sorbose, starch, sucrose, trehalose &
(c) Costin Stoica