Process for the production of L-amino acids using strains of the family enterobacteriaceae that contain an attenuated fruR gene
AssigneeDegussa AG
InventorsMechthild Rieping, Thomas Hermann
Life of this patent
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Abstract
A process for the production of L-amino acids, in particular L-threonine, in which the following steps are carried out: (a) fermentation of the microorganisms of the family Enterobacteriaceae producing the desired L-amino acid, in which the fruR gene or nucleotide sequences coding therefor are attenuated, in particular are switched off, (b) enrichment of the L-amino acid in the medium or in the cells of the bacteria, and (c) isolation of the L-amino acid.
Claims25
1-21. (canceled)
A process for producing an L-amino acid comprising:
- a) culturing a modified enterobacterium of the genus Escherichia in a medium for a time and under conditions suitable for producing said L-amino acid, and
- b) recovering or isolating said L-amino acid,
- wherein expression of the fruR (cra) gene has been eliminated from said modified Escherichia by:
- (i) inserting at least one base pair into the fruR gene,
- (ii) deleting at least one base pair from the fruR gene,
- (iii) generating a stop codon in the fruR gene by transitional mutagenesis, or
- (iv) generating a stop codon in the fruR gene by transversional mutagenesis;
- wherein said fruR (cra) gene is obtainable from Escherichia by PCR amplification using primer fruR‘5’-1 (SEQ ID NO:
- 3) and primer fruR‘3’-2 (SEQ ID NO:
- 6).
A modified enterobacterium of the genus Escherichia in which the expression of the fruR (cra) gene has been attenuated or eliminated compared to the corresponding unmodified Escherichia,
- wherein said fruR (cra) gene is obtainable from Escherichia by PCR amplification using primer fruR‘5’-1 (SEQ ID NO:
- 3) and primer fruR‘3’-2 (SEQ ID NO:
- 6).
Dependencies are inferred from the claim text.