Bifidobacterium longum subsp. longum
Cultural characteristics
Biochemical characters
Phylum “Actinobacteria”, Class Actinobacteria, Order Bifidobacteriales, Family Bifidobacteriaceae, Genus Bifidobacterium,
Bifidobacterium longum subsp. longum
(Reuter 1963)  Mattarelli, Bonaparte, Pot, Biavati, 2008. Two biovars: a and b.

Old synonym:
Bifidobacterium longum Reuter 1963.
Very elongated and thin cells with slightly irregular contours and rare branchings on
TPY agar.
Colonies are convex to pulvinate, soft, moist, shining or slimy, 2-5 mm in diameter
most strains develop a uniform turbidity in TPY broth; clearing is slow and the
sediment is viscous. Anaerobic. Optimum growth temperature is 36-38 ºC, range 22-
44 º
C. Grows at pH 4.5-7.5.
Isolated from faeces of human infants and adults, human vagina, suckling calves, and sewage. Biovar a is more frequent in human
adults and biovar b is more frequent in neonates.
Possesses a large variety of plasmids.
Non-pathogenic for man or animals.
  1. Biavati B, Mattarelli P, 2012.  Genus I. Bifidobacterium Orla-Jensen 1924. In: Parte et al. (ed). Bergey’s manual of systematic
    bacteriology: The Actinobacteria,Part A and B. Springer, New York, 171-206.
  2. Rogosa M. 1975. Genus III. Bifidobacterium Orla-Jensen 1924. In: Buchanan RE & Gibbons NE (ed). Bergey’s manual of
    determinative bacteriology, Eight Edition, The Williams & Wilkins Company, Baltimore, 669-676.
  3. Mattarelli P, Bonaparte C, Pot B, Biavati B, 2008.Proposal to reclassify the three biotypes of Bifidobacterium longum as three
    subspecies: Bifidobacterium longum subsp. longum subsp. nov., Bifidobacterium longum subsp. infantis comb. nov. and
    Bifidobacterium longum subsp. suis comb. nov. Int J Syst Evol Microbiol 58, 767-772.
  4. Sakata S, Kitahara M, Sakamoto M, Hayashi H, Fukuyama M, Benno Y, 2002. Unification of  Bifidobacterium infantis and
    Bifidobacterium suis as Bifidobacterium longum. Int J Syst Evol Microbiol  52, 1945-1951.
  5. Yanokura E, Oki K, Makino H, Modesto M, Pot B, Mattarelli P, Biavati B, Watanabe K, 2015. Subspeciation of Bifidobacterium longum
    by multilocus approaches and amplified fragment length polymorphism: description of B. longum subsp. suillum subsp. nov.,
    isolated from the faeces of piglets. Syst Appl Microbiol 38, 305-314.
  6. Modesto M, Michelini S, Sansosti MC, De Filippo C, Cavalieri D, Qvirist L, Andlid T, Spiezio C, Sandri C, Pascarelli S, Sgobarti B and
    Mattarelli P, 2018.  Bifidobacterium callitrichidarum sp. nov., from the faeces of the emperor tamarin (Saguinus imperator). IJSEM
    68, 141-148.
Positive results for alkaline phosphatase, arginine dihydrolase, arginine arylamidase (weak), esculin hydrolysis (weak), alpha- and
beta-galactosidase, glycine arylamidase, histidine arylamidase, leucine arylamidase, phenylalanine arylamidase (weak), proline
arylamidase, serine arylamidase (weak), tyrosine arylamidase (weak), acid production from arbutin, D- and L-arabinose, D-fructose,
D-galactose, D-glucose, gentibiose, D-lactose, maltose, melibiose, N-acetylglucosamine, raffinose, D-ribose, sucrose, and

Negative results for alanine arylamidase, alpha-arabinosidase, catalase, alpha-fucosidase, alpha- and beta-glucosidase, beta-
glucuronidase, indole production, nitrate reduction, N-acetyl-beta-glucosaminidase, urease, acid production from adonitol, amylose,
amylopectin, D- and L-arabitol, dextran, dulcitol, erythritol, L- and D-fucose, gluconate, D-glucuronate, glycerol, genibiose, glycogen, 2-
and 5-ketogluconate, D-mannitol,
alpha-methyl-D-glucopyranoside, pectin, porcine gastric mucin, rhamnose, L-sorbose, D-
tagatose, turanose, xylan and L-xylose.

Variable results for acid production from
amygdalin, cellobiose, esculin, D-galactosamine, D-glucosamine, inositol (weak),
inulin, D-mannose (biovar a is positive, while biovar b is negative), melezitose, alpha-methyl-D-mannoside, salicin, D-sorbitol,
starch, trehalose and D-xylose.
(c) Costin Stoica
Culture media
Biochemical tests
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