Cobalamin or vitamin B12

Cobalamin is a vitamin involved in the metabolism of every cell in the human body. It is needed for development and maintenance of the nervous system and brain. B12 vitamin is involved in DNA synthesis and regulation of the transcription. Only Bacteria and Archae are able to produce their own while animals. It is the largest and the most complex vitamin and it’s synthesis by organic chemistry required 91 post-doc and 23 Ph.D. students.

Because no plants are producing this vitamin vegan and vegetarian populations are at risk of developing symptoms of the deficiency. Those symptoms are severe and in a lot of case irreversibles. Symptoms of B12 deficiency are including nerves and brain damages, fatigue, depression, poor memory, mania, psychosis and pernicious anemia, an anemic disease that is usually fatal if not treated.

Production of cobalamin withPropionibacterium freudenreichii

The pathway of production of the vitamin B12 is huge in terms of genetic material needed for the production of all the enzymes and such cloning is not likely to works during the igem time scale. This is why we tried o find a strain which is already used in the industry to produce B12.
Among the over-producers strains used for cobalamin synthesis, propionibacterium was selected because it is widely used in cheese production (like emmental).

B12 daily requirement and toxicity

Children: 0.4-1.8ug/day
Pregnant Women: 2.6ug/day
Men:2.4ug/day
Cobalamin is not toxic even in doses well above the recommended daily allowance because it is a water soluble vitamin.
However this comes with a cost as water soluble vitamins are not stored in the body but excreted through urine.