Screening and distributing features of bacteria with hydantoinase and carbamoylase

Hydantoinase and carbamoylase are key biocatalysts for the production of optically pure amino acids from dl-5-substituted hydantoins (SSH). Out of 364 isolated strains with hydantoinase and carbamoylase at 45 °C, 24 strains showed efficient hydantoinase and carbamoylase activities. Among them, 17 produced l-amino acids, and 7 produced d-amino acids from both aromatic dl-5-benzylhydantoin and aliphatic dl-5-isopropylhydantoin. Most of the strains that were able to form l-amino acid belonged to genera Bacillus, Geobacillus, Brevibacillus, Aneurinibacillus, Microbacterium, and Kurthia. Phylogenetic relationships were investigated based on 16S rRNA from the hydantoinase-producing bacteria. Distinct tendencies toward certain genera were observed between most of the strains forming l-amino acids and d-amino acids from SSH. The results from this study can be utilized to develop new isolation technology of hydantoinase-producing microorganisms, and to understand metabolism and evolutionary origins of hydantoinase and carbamoylase among different bacteria.