Ammonia → Ammonium Aspartate

Participants

Reaction Conditions

Reaction Steps

According to the same procedure of Example 1, 600 g maleic acid was dissolved in deionized water, and 705 g of 25 wt % aqueous ammonia solution (molar ratio to maleic acid was about 2.0) was added thereon. The cells of Alcaligenes faecalis ATCC 8750 were added to 2 L of an ammonium maleate substrate solution (pH 8.4) containing 600 g maleic acid, and the substrate solution were gently stirred at 30° C. for 72 hours. After the reaction, ammonium L-aspartate was formed with a molar yield of 98.8% based on maleic acid. To the reaction solution from which the cells had been removed by centrifugation, was added 610 g maleic acid at 30° C. After the addition, a temperature of the solution was 37.0° C., and pH value thereof was 3.8. L-aspartic acid crystals were separated by filtration, so as to recover 1.5 L of mother liquors. The crude crystals was 769 g (excluding water) (88.0 wt % aspartic acid, 11.4 wt % maleic acid, 250 μm average crystal size). The crystals were washed with about 600 ml of water and dried so as to obtain 675 g of L-aspartic acid crystals (98.8 wt % aspartic acid, 0.77 wt % maleic acid, 100 μm average crystal size).

Provenance & Evidence