Research Highlights: Gut bacteria share ability to acquire vitamin B12 by “hugging” each other

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Gut bacteria share ability to acquire vitamin B12 by “hugging” each other

  • Mobile genetic elements or MGEs are genetic materials that can move around within a genome or move across different genomes.[1]
  • One popular example of mobile genetic elements in evolutionary context is the transfer of antibiotic resistance genes to another bacteria.
  • Horizontal transfer refers to the transfer of genetic material between organisms rather than the transmission of DNA from parent to offspring.[3]
  • Horizontal transfer of mobile genetic elements can shape the diversity of the human gut microbiome.
  • Mobile genetic elements can encode genes which benefits their host such as providing self-defense or the ability to compete for limited resources.
  • Vitamin B12 is an important nutrient required to enable gut colonization of Bacteriodetes.
  • Bacteriodetes are Gram-negative bacteria found anywhere in gastrointestinal tract, including the mouth and stomach, despite the presence of gastric juices and digestive enzymes.[4]
  • Researchers discovered a distinct type of mobile genetic elements in the Bacteriodetes responsible for the movement and exchange of the genes required for the transport of corrinoids.
  • Corrinoid is cobalt-containing molecule that function as enzyme cofactors in many organisms.[5]
  • An example of corrinoid is vitamin B12 (cobalamin).[6]
  • The newly discovered mobile genetic elements include two distinct groups of conjugative transposons and one group of bacteriophage.
  • Conjugative transposons are elements that can move from one bacterial cell to another through cell to cell contact.[7]
  • Researchers confirmed the activity of two of the conjugative transposons in vitro and in vivo.
  • The study highlights the importance of mobile genetic elements in distribution of corrinoid transporters in gut bacteria.


Frye, K. A., Piamthai, V., Hsiao, A., & Degnan, P. H. (2021). Mobilization of vitamin B12 transporters alters competitive dynamics in a human gut microbe. Cell reports, 37(13), 110164.








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