Journal of Bioscience and Bioengineering Vol. 98, No. 6 (December 2004) Cover

Structure of vitamin B12 (cyanocobalamin).

To increase the production of the vitamin by Propionibacterium freudenreichii, a known producer of this important vitamin in medical and food areas, more than 10 genes belonging to the hem, cob and cbi gene families involved in the vitamin B12 synthetic pathway of P. freudenreichii and other bacteria were overexpressed in the bacterium, and approximately 2-fold higher productivity was attained, confirming the greater usefulness of the bacterium for the production of vitamin B12 compared to chemical synthesis, which requires more than 70 complicated steps.

Related article: Piao, Y., Yamashita, M., Kawaraichi, N., Asegawa, R., Ono, H., and Murooka, Y., "Production of vitamin B12 in genetically engineered Propionibacterium freundenreichii", J. Biosci. Bioeng., vol. 98, 167-173 (2004).