Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Lactobacillaceae, Genus Lactobacillus [Group A lactobacilli (obligately
homofermentative), Lactobacillus delbrueckii phylogenetic-group], Lactobacillus gasseri Lauer and Kandler 1980.
Synonym: Lactobacillus acidophilus group B-1 of Johnson et al. (1980).
Gram-positive rods with rounded ends (0.6-0.8 x 3-5 μm) occurring singly and in
chains; formation of mini-cells and snakes is frequently observed. Nonspore-forming.
Surface colonies on BL (glucose blood-liver) agar plates were 0.5 to 2.0 mm in
diameter, circular to slightly irregular, entire, grayish-brown to brown, and rough.
Facultatively anaerobic. No growth at 15 ºC. Can grow at 45 ºC and in 4% NaCl
Isolated from human mouth and vagina and from the intestinal tract of man and animals; also found in wounds, urine, blood, and pus
of patients suffering from septic infections.
- 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,
- Fujisawa T., Benno Y., Yaeshima T. and Mitsuoka T., 1992. Taxonomic Study of the Lactobacillus acidophilus Group, with
Recognition of Lactobacillus gallinarum sp. nov. and Lactobacillus johnsonii sp. nov. and Synonymy of Lactobacillus acidophilus
Group A3 (Johnson et al. 1980) with the Type Strain of Lactobacillus amylovorus (Nakamura 1981). IJSB vol. 42, no.3, 487-491.
- Tanizawa Y, Tada I, Kobayashi H, Endo A, Maeno S, Toyoda A, Arita M, Nakamura Y, Sakamoto M, Ohkuma M and Tohno M, 2018.
Lactobacillus paragasseri sp. nov., a sister taxon of Lactobacillus gasseri, based on whole-genome sequence analyses . Int J
Syst Evol Microbiol 68, 3512-3517.
Obligately homofermentative (hexoses are fermented almost exclusively to lactic acid by the Embden-Meyerhof pathway; pentoses or
gluconate are not fermented).
Positive results for acid and alkaline phosphatase, cystine arylamidase, alpha-galactosidase, beta-glucosidase, N-acetyl-beta-
glucosaminidase, leucine arylamidase, fermentation of: amygdalin, arbutin, cellobiose, esculin, fructose, galactose, glucose (without
gas), gentibiose, lactose, mannose, N-acetyl-glucosamine, salicin, sucrose, turanose, tagatose, and trehalose.
Negative results for arginine dihydrolase, esterase lipase (C8), lipase (C14), alpha-fucosidase, alpha-glucosidase, beta-
galactosidase, beta-glucuronidase, indole production, lysine decarboxylase, alpha-manosidase, nitrate reduction, ornithine
decarboxylase, oxidase, trypsin, alpha-chymotrypsin, urease, valine arylamidase, Voges-Proskauer test, fermentation of: arabinose,
mannitol, melezitose, methyl alpha-D glucopyranoside, ribose, rhamnose, sorbose, and xylose.
Variable results for esterase C4, alpha-glucosidase, fermentation of maltose, melibiose, raffinose, and starch.
(c) Costin Stoica