Production of vitamin B₁₂ in genetically engineered Propionibacterium freudenreichii

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• 作者：Yongzhe  ; Piao ; Mitsuo  ; Yamashita  ; ;   ; ^{yamashita@bio.eng.osaka-u.ac.jp} ; Nami  ; Kawaraichi ; Ryo  ; Asegawa ; Hisayo  ; Ono ; Yoshikatsu  ; Murooka
• 关键词：vitamin B₁₂ ; hem ; cob ; cbi ; Propionibacterium freudenreichii
• 刊名：Journal of Bioscience and Bioengineering
• 出版年：2004
• 出版时间：2004
• 年：2004
• 卷：98
• 期：3
• 页码：167-173
• 全文大小：320 K

文摘

Since the chemical synthesis of vitamin B₁₂ requires more than 70 steps, the production of vitamin B₁₂ has been achieved by microorganism fermentation with additional brief chemical modifications. In an effort to increase the productivity of vitamin B₁₂, we tried to express 10 genes belonging to the hem, cob and cbi gene families involved in the synthesis of vitamin B₁₂ in Propionibacterium freudenreichii, which is a known producer of vitamin B₁₂. In a recombinant P. freudenreichii clone that harbored the expression vector containing a cobA, cbiLF, or cbiEGH, we obtained an increase in vitamin B₁₂ production of 1.7-, 1.9-, and 1.5-fold higher, respectively, than that in the microorganism without any cloned genes in the expression vector pPK705. The cobU and cobS genes caused a slight increase in the production of vitamin B₁₂. Furthermore, we achieved multigene expression in P. freudenreichii. In a recombinant P. freudenreichii clone that harbored an exogenous gene, hemA, from Rhodobacter sphaeroides and endogenous hemB and cobA genes, we successfully achieved the production of about 1.7 mg/l vitamin B₁₂, 2.2-fold higher than that produced by P. freudenreichii harboring pPK705.