Patent ID: 8435765

Claim:
A method of producing monatin or salt thereof, comprising: (a) contacting a cell with tryptophan, indole-3-lactic acid, a compound from which tryptophan, indole-3-lactic acid or a combination thereof can be produced in one or more steps, or a combination thereof; wherein the cell expresses: (i) a first polypeptide that facilitates the conversion of tryptophan, indole-3-lactic acid or a combination thereof to indole-3-pyruvate and is chosen from tryptophan aminotransferase (EC 2.6.1.27), tyrosine (aromatic) aminotransferase (EC 2.6.1.5), tryptophan dehydrogenase (EC 1.4.1.19), glutamate dehydrogenase (EC 1.4.1.2, 1.4.1.3, 1.4.1.4), phenylalanine dehydrogenase (EC 1.4.1.20), tryptophan-phenylpyruvate transaminase (EC 2.6.1.28), aspartate aminotransferase (EC 2.6.1.1), L-amino acid oxidase (EC 1.4.3.2), D-amino acid dehydrogenase (EC 1.4.99.1), D-amino acid oxidase (EC 1.4.3.3), D-amino acid (D-alanine) aminotransferase (EC 2.6.1.21), indolelactate dehydrogenase (EC 1.1.1.110), R-4-hydroxyphenyllactate dehydrogenase (EC 1.1.1.222), 3-(4)-hydroxyphenylpyruvate reductase (EC 1.1.1.237), lactate dehydrogenase (EC 1.1.1.27, 1.1.1.28, 1.1.2.3), (3-imidazol-5-yl) lactate dehydrogenase (EC 1.1.1.111), lactate oxidase (EC 1.1.3.-), and a combination thereof; (ii) a second polypeptide that facilitates the conversion of indole-3-pyruvate and a C3 carbon source to 2-hydroxy 2-(indole-3ylmethyl)-4-keto glutaric acid and is chosen from 4-hydroxy-2-oxoglutarate aldolase (KHG) (EC 4.1.3.16) or 4-hydroxy-4-methyl-2-oxoglutarate aldolase (ProA) (EC 4.1.3.17); and (iii) a third polypeptide that facilitates the conversion of 2-hydroxy 2-(indole-3ylmethyl)-4-keto glutaric acid to monatin and is chosen from tryptophan aminotransferase (EC 2.6.1.27), tyrosine (aromatic) aminotransferase (EC 2.6.1.5), tryptophan dehydrogenase (EC 1.4.1.19), glutamate dehydrogenase (EC 1.4.1.2, 1.4.1.3, 1.4.1.4), phenylalanine dehydrogenase (EC 1.4.1.20), aspartate aminotransferase (EC 2.6.1.1), L-amino acid oxidase (EC 1.4.3.2), D-amino acid dehydrogenase (EC 1.4.99.1), D-amino acid (D-alanine) aminotransferase (EC 2.6.1.21), and a combination thereof; (b) culturing the cell under conditions whereby monatin or salt thereof is produced; and (c) harvesting monatin or salt thereof.