Maleic Acid → Ammonium Aspartate

Participants

Reaction Conditions

Reaction Steps

According to the same procedure of Example 1, cells of Alcaligenes faecalis ATCC 8750 was added to 2 L of an ammonium maleate substrate solution containing 400 g of maleic acid, and the substrate solution was gently stirred at 30° C. for 24 hours. After the reaction, ammonium L-aspartate was formed with a molar yield of 99.0% based on maleic acid. To the reaction solution from which the cells had been removed by centrifugation, was added 1.23 kg of 33.3 wt % maleic acid aqueous solution at 30° C. After the addition, a temperature of the solution was 38.5° C., and pH value of thereof was 3.7. L-aspartic acid crystals were separated by filtration, so as to recover 2.37 L of mother liquors. The crude crystals were 481 g (excluding water) (93.6 wt % aspartic acid, 6.0 wt % maleic acid, 250 μm average crystal size). The crystals were washed with about 300 ml of water and dried so as to obtain 448 g (excluding water) of L-aspartic acid crystals (99.1 wt % aspartic acid weight, 0.50 wt % maleic acid, 200 μm average crystal size).

Provenance & Evidence