Identification of d-carbamoylase for biocatalytic cascade synthesis of d-tryptophan featuring high enantioselectivity. 
In this study, an enantioselective d-carbamoylase (AcHyuC) was identified from Arthrobacter crystallopoietes with optimum pH of 8.5, much more compatible with hydantoinase process than other reported d-N-carbamoylases.  AcHyuC has a substrate preference for aromatic carbamoyl-compounds.  The dynamic kinetic resolution (DKR) cascade was developed by combining this AcHyuC with hydantoin racemase from Arthrobacter aurescens (AaHyuA) and d-hydantoinase from Agrobacterium tumefaciens (AtHyuH) for enantioselective resolution of l-indolylmethylhydantoin into d-Trp.  The optimum pH of DKR cascade reaction was determined to be 8.0, and PEG 400 could facilitate the reaction.  As much as 80mM l-indolylmethylhydantoin could be fully converted to d-Trp within 12h at 0.5L scale, with 99.4% yield, >99.9% e.e.  and productivity of 36.6gL-1d-1.  This study provides a new d-carbamoylase compatible with the DKR cascade for efficient production of optically pure d-Trp from l-indolylmethylhydantoin.