METHOD FOR OBTAINING L-METHIONINE AND ORGANIC ACID Russian patent published in 2018 - IPC C12P13/12 C12P7/46 C12P7/54 

FIELD: biotechnology.

SUBSTANCE: group of inventions relates to biotechnology. Method for producing an L-methionine product and an organic acid is provided. Fermentable liquid containing a precursor of L-methionine, selected from O-acetylhomoserine and O-succinylhomoserine, and at least one impurity are provided. Precursor is subjected to enzymatic treatment to obtain a reaction liquid containing L-methionine, an organic acid selected from acetic acid and succinic acid, and at least one impurity. Reaction liquid is modified to form a stock crystallization solution, wherein the modification is one or more operations, selected from water removal, activated carbon treatment, addition of solute, pH adjustment, ion exchange, membrane filtration and bringing into contact with a water-soluble organic solvent. Crystallize L-methionine from the original crystallization solution to form crystalline L-methionine and L-methionine-depleted mother liquid. Second crystallization of L-methionine from the mother liquor is carried out and crystalline L-methionine is added to the initial crystallization solution. At least a portion of the organic acid is recovered from the mother liquor as an isolated organic acid. Resulting crystalline L-methionine has at least one characteristic, selected from: (i) a purity of more than 95 %; (ii) a content of less than 1 % organic acid; (iii) the content of the L-methionine precursor is greater than 1 RTB; (iv) at least one particular impurity content of more than 10 PPM and (v) less than 2 % of D-methionine. Resulting L-methionine product is used to prepare a food or feed composition. Inventions make it possible to obtain L-methionine in a yield of 93 % in the form of crystals of high purity to 99.2 %.

EFFECT: inventors make it possible to obtain L-methionine in a yield of 93 % in the form of crystals of high purity.

15 cl, 10 dwg, 7 ex, 10 tbl