| 초록 |
Coenzyme B12 is one of the largest and the most structurally complicated chemical in nature. Because it plays essential role in various metabolic functions and in many enzymatic reactions as a cofactor, its economic production are highly meaningful. Due to its complex structure, chemical synthesis is virtually impossible. Instead, B12 can be obtained from native producers such as Pseudomonas denitrificans and Klebsiella pneumoniae. However, a lack of genetic engineering tool for these microorganisms limits us to further develop B12 high producer. Rather than engineering native producers, reconstruction of B12 pathway in genetically well-known microorganisms such as an Escherichia coli could be more conceivable to achieve high production. In this study, we applied multiple synthetic biology based approaches in E. coli. Initially, the genes for B12 biosynthesis in P. denitrificans were introduced; the genes were expressed under a strong promoter and optimized 5' untranslated regions (5’-UTR) for maximum expression. Then, an amplification of precursor pool and developing an efficient screening device allowed further strain improvement for increased B12 production. |
