EFFICIENT PRODUCTION OF THE INDUSTRIAL BIOCATALYSTS HYDANTOINASE AND N-CARBAMYL AMINO-ACID AMIDOHYDROLASE - NOVEL NONMETABOLIZABLE INDUCERS

The biosynthesis of the hydantoin-hydrolysing enzymes hydantoinase and N-carbamyl amino acid amidohydrolase from Agrobacterium sp. IP I-671, a Gram-negative bacterium used as a biocatalyst for the production of enantiomerically pure (R) amino acids, was found to be highly inducible by the addition to the cultivation medium of different non-metabolizable thiolated hydantoins or pyrimidines. Among these inducers the hexacyclic pyrimidine thioderivatives were more potent than all the pentacyclic thiohydantoin compounds. Addition of 2,4-thiouracil to the cell cultures, at a Fate of 0.1 g (g cell dry mass)-1, led to no appreciable growth inhibition and yielded a biocatalyst exhibiting a 40-fold higher hydantoinase and a 15-fold higher N-carbamyl amino acid amidohydrolase activity than the corresponding inducer-free cultures.