Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster I (Clostridium sensu
stricto), Clostridium aurantibutyricum Hellinger 1944.
Gram-positive (Gram-negative in older cultures), straight rods, 0.5-0.8 x 2.8-6.3 µm,
occurring singly and in pairs. Motile by peritrichous flagella. Spores are oval,
subterminal, swelling the cell; sporulation occurs most readily on chopped-meat agar
slants incubated at 30 ºC for 1 week.
Surface colonies on blood agar plates are 1–2 mm in diameter, circular to slightly
irregular, raised to low convex, translucent, gray to pink-orange, dull, smooth, with a
mosaic internal structure. Blood is hemolysed.
Slight growth in broth with or without fermentable carbohydrate. Growth is inhibited by
6.5% NaCl and by 20% bile. Optimum growth at: 37 ºC and pH 7.0. No growth at 25 or
PYG broth cultures are turbid with a heavy, ropy, or viscous sediment and have a pH of
5.4 after incubation for 6 days. Abundant gas is detected in PYG deep agar cultures.
Major products of metabolism in PYG broth: acetate and lactate.
Isolated from rotting hibiscus stumps, flax, rotting potatoes, soil, sewage sludge; bovine, human infant, and adult feces.
Susceptible to chloramphenicol, clindamycin, erythromycin, penicillin G, and tetracycline.
Nonpathogenic for laboratory animals (mouse). 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., 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.
H2 is produced in large amounts. Milk reaction is positive (stormy fermentation; a solid curd is formed with 50% digestion in 3 weeks).
Meat digestion is negative.
Positive results for H2 production, esculin hydrolysis, gelatin hydrolysis, lipase, neutral red reduction, nitrate reduction, resazurin
reduction, starch hydrolysis, substrate utilized and/or acid produced from: arabinose (weak), cellobiose, dulcitol, fructose, galactose
(weak), glucose, glycogen, lactose, maltose, mannose (weak), melibiose (weak), raffinose, salicin (weak), sorbose, starch (weak) &
Negative results for casein hydrolysis, H2S production, indole production, lecithinase, urease, Voges-Proskauer reaction, substrate
utilized and/or acid produced from: amygdalin, glycerol, inositol, inulin, mannitol, melezitose, rhamnose, ribose, sorbitol, trehalose &
(c) Costin Stoica