Synonym: Lactobacillus cellobiosus Rogosa et al. 1953 has been reclassified as a later synonym of Lactobacillus fermentum
Beijerinck (1901) by Dellaglio et al. (2004).
Old synonyms: "Bacillus δ" von Freudenreich 1895, "Bacillus casei δ" von Freudenreich and Thoni 1904, "Lactobacterium fermentum"
(Beijerinck 1901) van Steenberge 1920, Betabacterium Jensenii Franck 1936 in Orla-Jensen 1943, Bacterium gayoni Muller-Thurgau
and Osterwalder 1917, Betabacterium longum Orla-Jensen 1919, Lactobacillus gayoni (Müller-Thurgau and Osterwalder) Pederson
1929, Lactobacillus longus (Orla-Jensen) Bergey et al. 1934, Lactobacterium longum (Orla-Jensen) Krasil’nikov 1949.
Lactobacillus fermentum cannot be definitely distinguished from Lactobacillus reuteri
by simple physiological tests. The genotypic methods used provide clear results.
|L. fermentum, Gram-positive, non-sporulated bacilli
|L. fermentum colonies on MRS Agar
Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Lactobacillaceae, Genus Lactobacillus [Group C lactobacilli
(obligately heterofermentative), Lactobacillus reuteri - phylogenetic group], Lactobacillus fermentum Beijerinck 1901.
Gram-positive rods, 0.5-0.9 x 3.0 µm, occuring singly or in pairs. Nonmotile.
Colonies are generally flat, circular or irregular to rough, often translucent;
nonpigmented, but rare strains produce rusty orange pigment. Grow at 41-42 ºC
(usually optimum for freshly isolated strains). No growth at 15 ºC. Can grow at 45 ºC.
Growth factor requirements: calcium pantothenate, niacin, and thiamine are essential;
Isolated from yeast, milk products, sourdough, fermenting plant material, manure,
sewage, and mouth and feces of humans, and intestines of pig, birds, cattle,
mouse and rat.
- Hammes W.P. and Hertel C., 2009. Genus I. Lactobacillus Beijerinck 1901. 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,
- Rogosa M., 1974. Genus I. Lactobacillus Beijerinck 1901. In: (Eds.) Buchanan R.E. and Gibbons N.E., Bergey’s Manual of
Determinative Bacteriology, Eighth Edition, The Williams & Wilkins Company, Baltimore, 576-593.
Obligately heterofermentative (hexoses are fermented to lactic and acetic acid
(ethanol), and CO2 via the phosphogluconate pathway; pentoses are fermented to
lactic acid and acetic acid by the related pentose phosphate pathaway).
Positive results for arginine hydrolysis (NH3 from arginine), fermentation of: fructose,
galactose, glucose (with gas production), gluconate, lactose, maltose, mannose
(weak reaction), melibiose, raffinose, ribose, and sucrose.
Negative results for nitrate reduction, fermentation of: adonitol, amygdalin, arabitol,
dulcitol, erythritol, esculin, glycerol, inositol, inulin, mannitol, melezitose, rhamnose,
salicin, sorbitol, sorbose, and starch. Admin note: catalase- and oxidase- negative.
Variable results for fermentation of: arabinose, cellobiose, trehalose, and xylose.
(c) Costin Stoica