OCHROBACTRUM-ANTHROPI NCIMB-40321 - A NEW BIOCATALYST WITH BROAD-SPECTRUM L-SPECIFIC AMIDASE ACTIVITY

Of 125 microorganisms that were able to use alpha-hydroxy acid amides as sole nitrogen source, Ochrobactrum anthropi NCIMB 40321 was selecte d for its ability to hydrolyse racemic amides L-selectively. The subst rate specificity of whole O. anthropi cells is remarkably wide and ran ges from alpha-H-alpha-amino-, alpha-alkyl-alpha-amino, N-hydroxy-alph a-amino acid amides to alpha-hydroxy-acid amides. After 50% conversion , both the L-acids formed and the remaining D-amides were present in > 99% enantiomeric excess, and ammonia accumulated in stoichiometric amo unts. Using mandelic acid amide as a model substrate, the hydrolysis w as optimized. Optimal rates were observed at pH 8.5 at 50-degrees-C. A t higher temperatures the initial rate was even higher; however, fairl y rapid inactivation occurred.