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Characteristics of methionine production by an engineered Corynebacterium glutamicum strain.
- Source :
-
Metabolic engineering [Metab Eng] 2007 Jul; Vol. 9 (4), pp. 327-36. Date of Electronic Publication: 2007 May 18. - Publication Year :
- 2007
-
Abstract
- A methionine-producing strain was derived from a lysine-producing Corynebacterium glutamicum through a process of genetic manipulation in order to assess its potential to synthesize and accumulate methionine during growth. The strain carries a deregulated hom gene (hom(FBR)) to abolish feedback inhibition of homoserine dehydrogenase by threonine and a deletion of the thrB gene (delta thrB) to abolish threonine synthesis. The constructed C. glutamicum MH20-22B/hom(FBR)/delta thrB strain accumulated 2.9 g/l of methionine by batch fermentation and showed resistance to methionine analogue ethionine at concentrations up to 30 mM. The growth of the strain was apparently impaired as a result of the accumulation of methionine biosynthetic intermediate, homocysteine. Production assays also revealed that the accumulation of methionine in the growth medium was transient and declined as the carbon source was depleted. During the period of methionine disappearance, the methionine biosynthetic genes were completely repressed in the engineered strains but not in the parental strain. After all, we have not only successfully constructed a methionine-producing C. glutamicum strain by genetic manipulation, but also revealed cellular constraints in attaining high yield and productivity.
- Subjects :
- Bacterial Proteins genetics
Corynebacterium glutamicum genetics
Corynebacterium glutamicum growth & development
Ethionine pharmacology
Homocysteine metabolism
Lysine biosynthesis
Lysine genetics
Methionine genetics
Mutation
Threonine biosynthesis
Threonine genetics
Bacterial Proteins metabolism
Corynebacterium glutamicum metabolism
Gene Expression Regulation, Bacterial
Methionine biosynthesis
Subjects
Details
- Language :
- English
- ISSN :
- 1096-7176
- Volume :
- 9
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Metabolic engineering
- Publication Type :
- Academic Journal
- Accession number :
- 17604670
- Full Text :
- https://doi.org/10.1016/j.ymben.2007.05.001