| 摘要 |
PCT No. PCT/GB94/02544 Sec. 371 Date May 9, 1996 Sec. 102(e) Date May 9, 1996 PCT Filed Nov. 18, 1994 PCT Pub. No. WO95/14002 PCT Pub. Date May 26, 1995A method of recovering a desired amino acid such as L-lysine from an aqueous solution containing the desired amino acid and impurities, includes the steps of passing the solution over a primary cation exchange resin to adsorb the desired amino acid onto the resin at a pH lower than the isoelectric point of the desired amino acid, eluting the desired amino acid from the resin using a suitable eluent having a pH higher than the isoelectric point of the desired amino acid to produce a first solution, passing the first solution over a secondary cation exchange resin to adsorb one or more of the impurities and to produce a second solution leaving the resin, collecting the second solution until the ratio of the concentrations of a selected impurity to the desired amino acid reaches a chosen value to produce a third solution which contains a lower level of impurities than the first solution, and recovering the desired amino acid from the third solution. This method avoids the need for a costly crystallization step to produce a final product.
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