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Construction of an L-isoleucine overproducing strain of Escherichia coli K-12.
- Source :
-
Bioscience, biotechnology, and biochemistry [Biosci Biotechnol Biochem] 1999 Apr; Vol. 63 (4), pp. 672-9. - Publication Year :
- 1999
-
Abstract
- The genes for a threonine deaminase that is resistant to feedback inhibition by L-isoleucine and for an active acetohydroxyacid synthase II were introduced by a plasmid into a L-threonine-producing recombinant strain of Escherichia coli K-12. Analysis of culture broth of the strain using 13C nuclear magnetic resonance suggested that alpha, beta-dihydroxy-beta-methylvalerate (DHMV) and alpha-keto-beta-methylvalerate (KMV), the third and the fourth intermediates in the L-isoleucine biosynthetic pathway from L-threonine, respectively, accumulated in the medium in amounts comparable to that of L-isoleucine. The ratio of accumulated L-isoleucine:DHMV:KMV were approximately 2:1:1. The concentration of accumulated L-isoleucine increased by twofold after the additional introduction of the genes for dihyroxyacid dehydratase (DH) and transaminase-B (TA-B), and the intermediates no longer accumulated. The resultant strain TVD5 accumulated 10 g/l of L-isoleucine from 40 g/l of glucose.
- Subjects :
- Acetolactate Synthase metabolism
Amino Acids metabolism
Base Sequence
Chromosomes, Bacterial genetics
Cloning, Molecular
Culture Media
Escherichia coli enzymology
Escherichia coli genetics
Magnetic Resonance Spectroscopy
Molecular Sequence Data
Plasmids genetics
Threonine Dehydratase metabolism
Acetolactate Synthase genetics
Escherichia coli metabolism
Isoleucine biosynthesis
Threonine Dehydratase genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0916-8451
- Volume :
- 63
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Bioscience, biotechnology, and biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 10361680
- Full Text :
- https://doi.org/10.1271/bbb.63.672