Phylum Firmicutes, Class Clostridia, Order Clostridiales, Family Clostridiaceae, Genus Clostridium, Cluster I (Clostridium sensu
stricto), Clostridium roseum (McCoy and McClung 1935) Cato, George and Finegold 1988.
Historical synonyms: Clostridium roseum McCoy and McClung 1935.
Gram-positive (but rapidly become Gram-negative), granulose positive rods, 0.7-0.9 x
3.2-4.3 µm, occuring singly, in pairs or in short chains. Motility is variable (vegetative
cells are motile and peritrichous; sporulating cells are sluggish or nonmotile). Spores
are oval, subterminal, swell the cell; sporulation occurs most rapidly in 5% corn meal
Surface colonies on blood agar plates are nonhemolytic, 4 mm in diameter, irregular,
flat, grayish-white with raised white centers, a dull rough surface, and a rhizoid
margin; on beef PYG agar, surface colonies are raised and smooth, with irregular
margins and a pink to orange pigmentation. Colonies become purplish-black after
exposure to air.
Cultures in PYG broth are slightly turbid with a peach to orange ropy sediment and a
pH of 4.1 after incubation for 6 days. Growth is stimulated by fermentable
carbohydrate and an atmosphere of 90% N2 / 10% CO2.
Optimum temperature for growth is 37 ºC; range 20-47 ºC. Abundant gas is formed in
PYG deep agar cultures. Products in PYG broth are butyric and acetic acids and
Isolated from German maize (probable habitat is the soil).
Nonpathogenic for guinea pigs or rabbits.
- 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,
Milk reaction is positive (curd production). Meat is not digested. Pectin is strongly fermented (final pH 4.8).
Positive results for hydrogen production, esculin hydrolysis, gelatin hydrolysis, H2S (in 0.25% glucose-tryptone-sulfite or 0.25%
glucose-tryptone-thiosulfate broth), substrate utilization and/or acid production from: arabinose, cellobiose, fructose, galactose,
glucose, lactose, mannose, rhamnose, salicin, starch, sucrose & xylose.
Negative results for indole production, lecithinase, lipase, nitrate reduction, starch hydrolysis, urease, substrate utilization and/or acid
production from: amygdalin, glycogen, inositol, inulin, maltose, mannitol, melezitose, melibiose, raffinose, ribose, sorbitol & trehalose.
(c) Costin Stoica