Purification and Characterization of Nitrilase Catalyzing Asymmetric Hydrolysis of Aminonitriles from Rhodococcus rhodochrous PA-34

The α-aminonitriles are used as intermediates in the chemical synthesis of racemic amino acids and appear to be potentially attractive substrates for their hydrolysis to amino acids by microbial nitrilases. Although the production of L-alanine by Acinetobacter sp. [1] and L-phenylglycine by Aspergillus fumigatus [2] have been reported, little is known about the mechanism of enantioselective hydrolysis of α-amino-nitriles by microorganisms. In the present paper, we report the production of optically active amino acids from α-aminonitriles by Rhodococcus rhodochrous PA-34 which was isolated from soil as a propionitrile utilizing microorganism and, the purification and characterization of the nitrilase which catalyzes this asymmetric hydrolysis.