New developments in the chemo-enzymatic production of amino acids.

Recent progress in the chemo-enzymatic production of amino acids is reviewed. Both recently developed commercial processes and potentially important new developments are discussed. Emphasis is placed on the use of acylases, aminopeptidases and hydantoinases. The discovery of D-specific enzymes in combination with racemases is an exciting and promising new area. Also, a goal-orientated approach towards the selective generation of these novel enzyme activities using in vivo protein engineering techniques is highlighted. The interest in dipeptide sweeteners has triggered a major research effort towards the production of L-phenylalanine and D-alanine. A number of methods for the production of these amino acids is briefly discussed. Finally, chemo-enzymatic methods for the synthesis of enantiomerically pure alpha-alkyl-alpha-amino acids are reviewed.