Cells obtained from growth of Achromobacter eurydice, Pseudomonas aromatica and Pseudomonas putida on L-phenylalanine containing medium catalyzed the enzymatic acyloin condensation of phenylpyruvic acid 1 and acetardehyde 2 by phenylpyruvate decarboxylase to produce 3-hydroxy-1-phenyl-2-butanone 3. The acyloin condensation by Achramobacter eurydice and P. aromatica was stereoselective, providing the 3R enantiomer 3a with enantiomeric excess (ee) of 95% and 84%, respectively. A partially purified enzyme was prepared from the cell free extract of Achromobacter eyrydice. The acyloin product 3a was obtained in 45% yield with an ee of 91% by using this partially purified preparation of phenylpyruvate decarboxylase. (C) 2000 Elsevier Science Ltd. Ail rights reserved.