Bifidobacterium adolescentis

Bifidobacterium adolescentis From MicrobeWiki, the student-edited microbiology resource Jump to: navigation, search

Contents [hide]

   * 1 Classification
         o 1.1 Higher order taxa
         o 1.2 Genus
   * 2 Description and significance
   * 3 Genome structure
   * 4 Cell structure and metabolism
   * 5 Ecology
   * 6 Pathology
   * 7 Application to Biotechnology
   * 8 Current Research
   * 9 References

[edit] Classification [edit] Higher order taxa

Bacteria; Actinobacteria; Actinobacteridae; Bifidobacteriales; Bifidobacteriaceae; Bifidobacterium; Bifidobacterium adolescentis ATCC 15703 [edit] Genus

Bifidobacterium adolesecentis

Species

B. angulatum; B. animalis; B. asteroides; B. bifidum; B. boum; B. breve; B. catenulatum; B. choerinum; B. coryneforme; B. cuniculi; B. dentium; B. gallicum; B. gallinarum; B indicum; B. longum; B. magnum; B. merycicum; B. minimum; B. pseudocatenulatum; B. pseudolongum; B. psychraerophilum; B. pullorum; B. ruminantium; B. saeculare; B. scardovii; B. simiae; B. subtile; B. thermacidophilum; B. thermophilum; B. urinalis; B. sp.

NCBI: Taxonomy [edit] Description and significance

Bifidobacterium adolescentis. [A helpful bacterium that is an inhabitant of the human intestinal tract, from The Food and Development Research Centre, Canada. Diane Monpetit.

Bifidobacterium adolescentis are normal inhabitants of healthy human and animal intestinal tracts. Colonization of B. adolescentis in the gut occurs immediately after birth. Their population in the gut tends to maintain relative stability until late adulthood, where factors such as diet, stress, and antibiotics causes it to decline. This species was first isolated by Tissier in 1899 in the feces of breast-fed newborns. Tissier was the first to promote the therapeutic use of bifidobacteria for treating infant diarrhea by giving them large doses of bifidobacteria orally. Since then, their presence in the gut has been associated with a healthy microbiota. The correlation between the presence of bifidobacteria and gastrointestinal health has produced numerous studies focusing on gastrointestinal ecology and the health-promoting aspects that bifidobacteria are involved in. Obtaining more information about specific strains of bifidobacteria and their roles in the gastrointestinal tract have been on the rise as these probiotic organisms are being used as food additives, such as dairy products. Their name is derived from the observation that these bacteria often exist in a Y-shaped, or bifid form.

[edit] Genome structure

Bifidobacterium adolescentis averages 2.1 Mbp in length. Its form is either an elongated, thin irregular rod-, Y- or V-shape. Containing one membrane and a circular chromosome, B. adolescentis is not mobile. B. adolescentis has 2,089,645 nucleotides, including 1,631 protein-encoding genes and 69 RNA genes. To date, no plasmids have been detected in B. adolescentis.

[edit] Cell structure and metabolism

B. adolescentis is a gram-positive organism. Each species of bifidobacteria contain different components in their cell walls; B. adolescentis' cell wall is made made primarily of murein, containing Lys- or Orn-D-Asp within its peptide chains. Its polysaccharide components include glucose and galactose. Myristic, palmitic, and oleic are the major fatty acids within the cell wall. Leipoteichoic acids on the cell wall's surface function to help the organism adhere to the intestinal wall.

Bifidobacteria are anaerobes (though some can tolerate oxygen, using enzymes superoxide dismutase and catalase in thier defense against the toxic effects of superoxide and hydrogen peroxide). B. adolescentis, like all of the bifidobacteria species, can ferment lactose and grow well in milk, as well as use many carbohydrates. Glucose is fermented using the fructose-6-phosphate pathway which requires the enzyme, fructose-6-phosphoketolase(F6PPK). As a result of metabolizing various carbohydrates, bifidobacteria produce short-chain fatty acids such as propionate, butyrate, and acetate to be used as energy sources.

Nitrogen metabolism is also observed in bifidobacteria, using ammonium sulfate as its nitrogen source.

Bifidobacteria have also been found to synthesize vitamins; B. adolescentispredominantly synthesizes cyanocobalamin and nicotine, as well as thiamin, folic acid, and pyridoxine. B. adolescentis' ability to produce vitamins plays a beneficial role in increasing the nutritional quality of fermented dairy products when added in.

[edit] Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc. [edit]

Pathology

Bifidobacterium adolescentis is a non-pathogenic organism.

[edit] Application to Biotechnology

B. adolescentis synthesizes various B vitamins that are beneficial to the nutritional health of the host organism. Vitamins that are synthesized included thiamin(B1), pyridoxine(B6), folic acid(B9), nicotine, cyanocobalamin(B12), ascorbic acid(Vitamin C), Biotin, and Riboflavin.

Also, bifidobacteria contain phytase activity, enabling the dephosphorylation of phytic acid (myo-inositol hexaphosphate, IP6) and produce several myo-inositol phosphate intermediates, IP3, IP4, and IP5. IP6 has been shown to have antinutritional effects by limiting the dietary bioavailability of amino acids and minerals such as Ca2+, Z2+, and Fe2+. However, bifidobacteria reduce these effects by dephosphorylating IP6 into lower phosphorylated products during food processing and gastrointestinal transit. Additionally, these lower phosphorylated intermediates are also involved in regulating vital cellular functions. [edit] Current Research

1. Bifidobacterium adolescentis as a producer of folate in the colon: testing various strains of Bifidobacterium revealed their ability to produce folate. Experiments analyzing cultured samples of feces showed that the addition of B. adolescentis may increase the folate concentration in a colonic environment. Results provided positive insight into the use of probiotics in preventing folate deficiency in colonic epithelial cells as well as more efficiently protecting the colon against inflammation and cancer.

2. Dietary Factors in inflammatory disease.

3.

[edit] References

Genome Project: Bifidobacterium adolescentis ATCC 15703 project at Gifu University, Life Science Research Center, Japan/NCBI, Bethesda, USA

Also see: Bifidobacterium (Microbe Wiki), Bifidobacterium (Wikipedia)

Arunachalam, Kantha D., et al. The Role of Bifidobacteria in Nutrition, Medicine, and Technology. Nutrition Research. Vol 19, No. 10, pp. 1559-1597, 1999. Elsevier Science Inc., USA.

Haros, Monica. Phytase activity as a novel metabolic feature in Bifidobacterium. FEMS Microbiology Letters 247, 2005, pp.231–239.

Klijn, Adrianne, et al. Lessons from the genomes of bifidobacteria. FEMS Microbiology Reviews, 2005, 29(3), 491–509.

Pompei, Anna, et al. Folate Production by Bifidobacteria as a Potential Probiotic Property. Applied and Environmental Microbiology, January 2007, p. 179-185, Vol. 73, No. 1

Shah, Shinil. Dietary Factors in the Modulation of Inflammatory Bowel Disease Activity. Medscape General Medicine. March 2007, 9(1):60. ©2007 Medscape

Edited by student of Rachel Larsen and Kit Pogliano