Patent ID: 8563278

Claim:
A process for producing monatin or a salt thereof comprising, under conditions in which monatin is produced: (a) providing tryptophan or salt thereof, (b) contacting tryptophan or salt thereof with a first polypeptide that facilitates converting tryptophan or salt thereof to indole-3-pyruvic acid or a salt thereof, wherein said first polypeptide is selected from the group consisting of an L-tryptophan transaminase, an aspartate transaminase, an L-amino acid oxidase and a D-amino acid oxidase; (c) contacting said indole-3-pyruvic acid or a salt thereof with a second polypeptide that facilitates converting indole-3-pyruvic acid or a salt thereof to 4-(indol-3-ylmethyl)-4-hydroxy-2-oxoglutaric acid or a salt thereof in the presence of oxaloacetic acid or a salt thereof or pyruvic acid or a salt thereof, wherein said second polypeptide is selected from the group consisting of 4-hydroxy-4-methyl-2-oxoglutarate aldolase and 4-hydroxy-2-oxoglutarate aldolase; (d) contacting said 4-(indol-3-ylmethyl)-4-hydroxy-2-oxoglutaric acid or a salt thereof with a third polypeptide that facilitates converting 4-(indol-3-ylmethyl)-4-hydroxy-2-oxoglutaric acid or a salt thereof to monatin or salt thereof, wherein said third polypeptide is selected from the group consisting of a tryptophan transaminase, a tyrosine transaminase, a tryptophan dehydrogenase, an aspartate transaminase, a glutamate dehydrogenase, a phenylalanine dehydrogenase, a D-amino acid dehydrogenase, and a D-amino acid transaminase, thereby producing monatin or a salt thereof.