Process for the preparation of L-amino acids using a gene encoding 6-phosphogluconate dehydrogenase
OwnerL. K. Dunican, Ashling McCormack +3inventors
InventorsL. K. Dunican, Ashling McCormack, Cliona Stapelton, Kevin Burke, Bettina Mockel
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Abstract
The invention relates to a process for the preparation of L-amino acids. The process involves fermenting an L-amino acid producing coryneform bacteria in a culture medium, concentrating L-amino acid produced by the fermenting in the culture medium or in the cells of the bacteria, and isolating the L-amino acid produced. The bacteria has an overexpressed gene encoding 6-phosphogluconate dehydrogenase and a decreased or switched off gene encoding pyruvate oxidase. The L-amino acid may be L-lysine, L-threonine, L-isoleucine or L-tryptophan.
Claims9
A process for the preparation of L-lysine, comprising:
- a) fermenting an L-lysine producing coryneform bacteria in a culture medium, the bacteria having at least an overexpressed gene encoding 6-phosphogluconate dehydrogenase;
- b) concentrating L-lysine produced by said fermenting in the culture medium or in the cells of the bacteria;
- and
- c) isolating the L-lysine produced;
- wherein intracellular activity of pyruvate oxidase encoded by a pyruvate oxidase gene is decreased or switched off in the bacteria.
A process for the preparation of an L-amino acid, comprising:
- a) fermenting an L-amino acid producing coryneform bacteria in a culture medium, the bacteria having at least an overexpressed gnd gene encoding 6-phosphogluconate dehydrogenase;
- b) concentrating L-amino acid produced by said fermenting in the culture medium or in the cells of the bacteria;
- and
- d) isolating the L-amino acid produced;
- wherein intracellular activity of pyruvate oxidase encoded by a pyruvate oxidase gene is decreased or switched off in the bacteria;
- and
- wherein the L-amino acid is selected from the group consisting of L-threonine, L-isoleucine and L-tryptophan.
An L-lysine producing coryneform microorganism having increased intracellular activity of 6-phosphogluconate dehydrogenase and decreased intracellular activity of pyruvate oxidase.
The plasmid vector pEC-T18mob2 deposited under the designation DSM 13244 in E. coli K-12 DH5.
Dependencies are inferred from the claim text.