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subsp. lactis
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Lactobacillus delbrueckii subsp. lactis
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Taxonomy
Morphology
Cultural characteristics
Biochemical characters
Ecology
Pathogenicity
References
Phylum Firmicutes, Class Bacilli, Order Lactobacillales, Family Lactobacillaceae, Genus Lactobacillus [fermentation-type Group A
lactobacilli (obligately homofermentative), Lactobacillus delbrueckii phylogenetic-group], Lactobacillus delbrueckii subsp. lactis
(Orla-Jensen 1919) Weiss, Schillinger and Kandler 1984.
Historical synonyms: Thermobacterium lactis Orla-Jensen 1919, Lactobacillus leichmannii (Henneberg) Bergey, Harrison, Breed,
Hammer and Huntoon 1923, Lactobacillus lactis (Orla-Jensen 1919) Bergey et al. 1934, Bacillus lactis acidi Leichmann 1896,
Bacterium lactis acidi (Leichmann 1896) Leichmann 1896, Lactobacillus lactis-acidi (Leichmann 1896) Bergey et al.1923,
Lactobacterium caucasicum var. lactis (Orla-Jensen 1919) Krasilnikov 1949.
Gram-positive rods , under 2 µm wide, often appearing as long forms with a tendency
to grow into threads, often strongly curling, occurring singly or in pairs in young
cultures. Internal granulation may be revealed with methylene blue stain. Nonmotile.
Colonies are normally rough, 1-3 mm in diameter and non-pigmented being white to
light gray. Optimum temperature for growth is 40-44 ºC. Variable growth at 48-52 ºC.
Can grow at 45 ºC. No growth at 15 ºC. Optimum pH for growth 5.5-6.2. Can grow at
pH 5.0. Growth factor requirements: pantothenic acid and niacin generally essential;
riboflavin, folic acid, vitamin B12, and thymidine are essential for particular strains.
Isolated from milk, cheese, compressed yeast, and grain mash.
Have phages belonging to the families Myoviridae and Siphoviridae.
Produce pyroglutamic acid (2-pyrolidone-5 carboxylic acid) with activity against Bacillus subtilis, Panothoea agglomerans, and
Pseudomonas spp.
Nonpathogenic.
- 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,
Springer, 465-511.
- 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.
- Kudo Y, Oki K, Watanabe K. Lactobacillus delbrueckii subsp. sunkii subsp. nov., isolated from sunki, a traditional Japanese
pickle. Int J Syst Evol Microbiol 2012; 62:2643-2649.
Obligately homofermentative (hexoses are fermented almost exclusively to lactic acid by the Embden-Meyerhof pathway; pentoses or
gluconate are not fermented).
Positive results for fermentation of: amygdalin, fructose, glucose (without gas production), lactose, maltose, mannose, salicin,
sucrose, and trehalose.
Negative results for esculin hydrolysis, indole production, H2S production, catalase, oxidase, gelatin liquefaction, casein digestion,
nitrate reduction, fermentation of: arabinose, gluconate, mannitol, melezitose, melibiose, raffinose, rhamnose, ribose, sorbitol, and
xylose.
Variable results for arginine hydrolysis, fermentation of: cellobiose, esculin (weak) & galactose.
(c) Costin Stoica
Differential characters of Lactobacillus delbrueckii subspecies:
Legend: + positive 90-100%, - negative 90-100%, [+] positive 75-89%, [-] negative 75-89%, d positive 25-74% of strains