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US 7,598,062 B2Granted
Process for the production of L-amino acids using strains of the family enterobacteriaceae that contain an attenuated fruR gene
AssigneeEvonik Degussa GmbH
InventorsMechthild Rieping, Thomas Hermann
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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.
Claims20
A fed-batch or repeated fed-batch process for producing an L-amino acid comprising:
- a) culturing an 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, and determining the amount of the isolated L-amino acid,
- wherein said Escherichia enterobacterium has been modified to eliminate expression of the fruR (cra) gene 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 encodes the polypeptide of SEQ ID NO:
- 2.
6 more elements
Dependencies are inferred from the claim text.