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.degree. 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.degree.
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.
