Methods for producing L-aspartic acid

摘要

This invention relates to a method for producing L-aspartic acid comprising treating an ammonium fumarate solution with aspartase to generate an ammonium L-aspartate solution; adding fumaric acid to the solution; and then crystallizing L-aspartic acid from the solution, wherein fumaric acid is added to the ammonium L-aspartate solution after the solution has been heated to 50 to 130° C. in an amount 0.4 to 0.8 times the total amount of fumarate and the L-aspartate contained therein in terms of mole, and the resultant mixture is once turned into a homogeneous solution by applying thereto a shearing force, and then L-aspartic acid is deposited therefrom, or wherein the solution is cooled at a rate of 0.1-5° C./min from the temperature at which fumaric acid is added thereto to the temperature at which crystallized L-aspartic acid is separated therefrom, to thereby deposit L-aspartic acid.