METHOD OF PRODUCING L-METHIONINE Russian patent published in 2020 - IPC C12P13/12 C12P11/00 

FIELD: biotechnology.

SUBSTANCE: invention relates to biotechnology, particularly to a method of producing L-methionine by an enzymatic reaction between a precursor of L-methionine, dimethyl disulphide (DMDS) and an organic compound reducing agent. Method comprises preparing mixture containing 1) DMDS, 2) a catalytic amount of an amino acid containing a thiol group, or a peptide with a thiol group, 3) a catalytic amount of reductase which catalyses reduction of a disulphide bridge of an amino acid containing a thiol group, or a peptide with a thiol group, 4) organic reducing compound in stoichiometric amount with respect to DMDS, 5) catalytic amount of dehydrogenase catalyzing reaction of dehydration of said organic reducing compound, 6) catalytic amount of cofactor, which is common for dehydrogenase and reductase. Fermentation is carried out to obtain methyl mercaptan (CH₃SH). L-methionine precursor is introduced. This precursor reacts with CH₃SH. Formed L-methionine is recovered.

EFFECT: invention enables to avoid manipulations with methyl mercaptan or at least reduce their volume, generating methyl mercaptan by enzymatic catalysis of DMDS immediately before synthesis of L-methionine or in situ in a reactor for synthesis of L-methionine.

16 cl, 2 dwg, 2 ex