Formation of Aliphatic and Aromatic a-Hydroxy Ketones by Zygosaccharomyces bisporus

Zygosaccharomyces bisporus, Acyloin Formation, Pyruvate Decarboxylase The wild-type yeast strain Zygosaccharomyces bisporus CBS 702 produced a-hydroxyketones (acyloins) from amino acid precursors after transamination to the corresponding 2-oxo acids. The key enzyme of the subsequent decarboxylation and C C bond forming reaction, pyruvate decarboxylase (PD C), was examined for its substrateand stereo-specificity. A wide variety of saturated and unsaturated aliphatic and aromatic aldehydes was suc­ cessfully converted to acyloins. 19 of the biotransformation products identified had not been reported as natural substances before. Product yields were strongly affected by substrate structure.