Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster XIVa (non-Clostridium
sensu stricto), Clostridium propionicum Cardon and Barker 1946.
Gram-positive (rapidly become Gram-negative), straight or slightly curved rods with
tapered or rounded ends, 0.5-0.8 x 1.3-5.0 µm, occuring in pairs, singly or in short
chains. Motile by peritrichous flagella. Spores are oval, subterminal, and swell the
cell; sporulation occurs most readily on egg yolk agar plates or in PY broth cultures.
Surface colonies on blood agar plates are pinpoint, circular, convex, translucent,
gray, dull with a slightly shiny outer rim, smooth, with an entire to slightly scalloped
margin. Nonhemolytic. Cultures in PYG broth have a smooth sediment, with
turbidity, and a pH of 6.0-6.2 after incubation for 1 week. Slight to no growth in
nutrient broth without fermentable carbohydrate.
Optimum temperature for growth is 25-30 ºC. No growth at 45 ºC. Alanine, serine,
threonine, lactate, pyruvate, or acrylate is required for growth. Moderate amounts of
gas are detected in PYG deep agar cultures. Products in PYG broth are propionate,
isovalerate, isobutyrate, butyrate; abundant hydrogen is produced.
Isolated from black mud from San Francisco Bay, California, USA.
Nonpathogenic for laboratory animals. 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 is negative.
Positive results for ammonia production, H2S production & resazurin reduction.
Negative results for casein hydrolysis, esculin hydrolysis, gelatin hydrolysis, indole production, lecithinase, lipase, nitrate reduction,
starch hydrolysis, urease, Voges-Proskauer, substrate utilization and/or acid production from: amygdalin, arabinose, cellobiose,
dulcitol, esculin, fructose, galactose, glucose, glycogen, glycerol, inositol, inulin, lactose, maltose, mannitol, mannose, melezitose,
melibiose, raffinose, rhamnose, ribose, salicin, sorbitol, sorbose, starch, sucrose, trehalose & xylose.
(c) Costin Stoica