Production of vitamin B12 by immobilized cells of a propionic acid bacterium

Busaba Yongsmith, Kenji Sonomoto, Atsuo Tanaka, Saburo Fukui

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)


The ability of immobilized cells of propionic acid bacteria to form vitamin B12 has been investigated. Propionibacterium arl AKU 1251 having a considerable activity to produce the vitamin was selected as a test organism among six strains of propionic acid bacteria tested. The whole cells were entrapped with urethane prepolymers, photo-crosslinkable resin prepolymers or several other materials such as κ-carrageenan, agar or sodium alginate, and their vitamin B12 productivity was compared. Based on the criteria of the convenience of preparation and the stability of the cell-entrapping gels, a hydrophilic urethane prepolymer, PU-9, was employed as gel material. Satisfactory vitamin B12 production was obtained when 5-10 g of wet cells precultured to the late exponential growth phase were entrapped with 1 g of the prepolymer. Addition of a suitable amount of cobaltous ion and of 5,6-dimethyl benzimidazole to the culture medium was effective for the production of the vitamin by the immobilized cells. The repeated use of the immobilized cells was successfully achieved when a suitable amount of cells were entrapped and allowed the proliferation of cells inside gel matrices.

Original languageEnglish
Pages (from-to)70-74
Number of pages5
JournalEuropean Journal of Applied Microbiology and Biotechnology
Issue number2-3
Publication statusPublished - Jun 1982

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Microbiology


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