Effect of cell membrane of Agrobacterium radiobacter on enhancing D-amino acids production from racemic hydantoins

摘要

An interesting phenomenon was observed that the existence of the intact cell membrane can enhance the D-amino acids production from D,L-5 substituted hydantoins by reacting with the whole cells of Agrobacterium radiobacter. Two intracellular enzymes were involved in the reaction process. The first enzyme D-hydantoinase converted hydantoins to carbamoyl derivatives which were further converted to D-amino acids by D-amidohydrolase. The amount of D-amino acids produced from hydantoins by the intact cells were 1.8-2.4 fold higher than the toluene treated cells. In addition, by using the intact cells the amount D-amino acids produced from hydantoins was about 10 intermediate carbamoyl derivatives was confirmed by a simple mathematical model to the main factor for the better performance of the intact cells for D-amino acid production. Besides, the low intracellular enzymes activities also contributed to the effect of intact cell membrane on enhancing the D-amino acid production.