Process for the production of L-amino acids using strains of the Enterobacteriaceae family which contain an enhanced fadR or iclR gene
AssigneeEvonik Degussa GmbH
InventorsMechthild Rieping, Nicole Siebelt
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Abstract
This invention relates to a process for the production of L-amino acids, in particular L-threonine, in which the following steps are performed: a) fermentation of microorganisms of the Enterobacteriaceae family which produce the desired L-amino acid, in which at least one or more of the genes, selected from the group iclR and fadR, or nucleotide sequences coding therefor, are enhanced, in particular overexpressed, b) accumulation of the desired L-amino acid in the medium or in the cells of the bacteria and c) isolation of the desired L-amino acid.
Claims19
A process for preparing an L-amino acid selected from the group consisting of L-threonine, L-lysine, and L-valine comprising:
- a) fermenting a suitable medium with a modified microorganism from the genus Escherichia which produces said L-amino acid, wherein said modified microorganism has been transformed with a vector that over-expresses the iclR gene and/or the fadR gene, compared to the corresponding untransformed Escherichia and wherein L-amino acid production in said modified Escherichia that over-expresses the iclR gene and/or the fadR gene is enhanced compared to the corresponding untransformed Escherichia;
- and
- b) recovering the L-amino acid;
- wherein the coding sequence of the iclR gene can be isolated from the DNA of an Escherichia by (PCR) and the primers iclR3 (SEQ ID NO:
- 3) and iclR4 (SEQ ID NO:
- 4), and
- wherein the coding sequence of the fadR gene can be isolated from the DNA of Escherichia using polymerase chain reaction (PCR) and the primers fadR3 (SEQ ID NO:
- 1) and fadR4 (SEQ ID NO:
- 2).
A process for preparing an L-amino acid selected from the group consisting of L-threonine, L-lysine, and L-valine comprising:
- a) fermenting in a suitable medium a modified microorganism from the genus Escherichia which produces said L-amino acid, wherein said modified Escherichia has been transformed with a vector that over-expresses the iclR gene and/or the fadR gene, compared to the corresponding untransformed Escherichia and wherein L-amino acid production in said modified Escherichia that over-expresses the iclR gene and/or the fadR gene is enhanced compared to the corresponding untransformed Escherichia;
- and
- recovering the L-amino acid;
- wherein the coding sequence of the iclR gene encodes a polypeptide comprising SEQ ID NO:
- 6 and the coding sequence of the fadR gene encodes a polypeptide comprising SEQ ID NO:
- 8.
A process for preparing L-threonine comprising:
- a) fermenting a suitable medium with an L-threonine-producing Escherichia strain which has been modified to over-express the coding sequence of its iclR gene and/or its fadR gene, compared to the corresponding unmodified Escherichia coli strain, and which produces a greater amount of L-threonine compared to the corresponding unmodified Escherichia strain;
- and
- b) recovering the L-threonine;
- wherein the coding sequence of the iclR gene can be isolated from the DNA of Escherichia coli by PCR using the primers iclR3 (SEQ ID NO:
- 3) and iclR4 (SEQ ID NO:
- 4), and
- wherein the coding sequence of the fadR gene can be isolated from the DNA of Escherichia coli by PCR using the primers fadR3 (SEQ ID NO:
- 1) and fadR4 (SEQ ID NO:
- 2).
A process for preparing L-lysine comprising:
- a) fermenting a suitable medium with an L-lysine-producing Escherichia strain which has been modified to over-express the coding sequence of its iclR gene and/or its fadR gene, compared to the corresponding unmodified Escherichia, and which produces a greater amount of L-lysine compared to the corresponding unmodified Escherichia strain;
- and
- b) recovering the L-lysine;
- wherein the coding sequence of the iclR gene can be isolated from the DNA of Escherichia by PCR using the primers iclR3 (SEQ ID NO:
- 3) and iclR4 (SEQ ID NO:
- 4), and
- wherein the coding sequence of the fadR gene can be isolated from the DNA of Escherichia by PCR using the primers fadR3 (SEQ ID NO:
- 1) and fadR4 (SEQ ID NO:
- 2).
A process for preparing L-valine comprising:
- a) fermenting a suitable medium with an L-valine-producing Escherichia strain which has been modified to over-express the coding sequence of its iclR gene and/or its fadR gene, compared to the corresponding unmodified Escherichia, and which produces a greater amount of L-valine compared to the corresponding unmodified Escherichia strain;
- and
- b) recovering the L-valine;
- wherein the coding sequence of the iclR gene can be isolated from the DNA of Escherichia by PCR using the primers iclR3 (SEQ ID NO:
- 3) and iclR4 (SEQ ID NO:
- 4), and
- wherein the coding sequence of the fadR gene can be isolated from the DNA of Escherichia by PCR using the primers fadR3 (SEQ ID NO:
- 1) and fadR4 (SEQ ID NO:
- 2).
Dependencies are inferred from the claim text.