Ammonia → Ammonium Aspartate

Participants

Reaction Conditions

Reaction Steps

According to the same procedures of Example 1, 200 g maleic acid was dissolved in deionized water, and 235 g of 25 wt % aqueous ammonia solution was added thereon. The cells of Alcaligenes faecalis ATCC 8750 was added to 2 L of an ammonium maleate substrate solution containing 200 g 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 205 g maleic acid at 30° C. After the addition, a temperature of the solution was 32.5° C., and pH thereof was 3.7. L-aspartic acid crystals were separated by filtration, so as to recover 1.75 L of mother liquors. On the other hand, the amount of the filtrated crude crystals of L-aspartic acid was 245 g (excluding water) (91.4 wt % aspartic acid, 8.0 wt % maleic acid, 300 μm average crystal size). The crystals were washed with about 300 ml of water and dried so as to obtain 225 g of L-aspartic acid crystals (99.0 wt % aspartic acid, 0.69 wt % maleic acid, 150 μm average crystal size).

Provenance & Evidence