Production of phenylacetylcarbinol by various yeast species

Measurements of tolerance to the addition of benzaldehyde were carried out with six yeast species:Hansenula anomala, Brettanomyces vini Peynaud et Domercq, strain X,Saccharomyces carlsbergensis, Saccharomyces cerevisiae R XII,Saccharomyces ellipsoideus andTorula utilis. The techniques used were: comparison of evolution of carbon dioxide with and without benzaldehyde and production of phenylacetylcarbinol after a single addition of benzaldehyde (0.2%) and after four additions (total of 0.8%). The highest decarboxylase activity in the presence of benzaldehyde was found withHansenula anomala, Saccharomyces carlsbergensis andSaccharomyces cerevisiae. InHansenula anomala, benzaldehyde caused a 16% inhibition of fermentation, in the other cultures inhibition lay between 35.5 and 63.2%. After a single addition of benzaldehyde the greatest amount of phenylacetylcarbinol was formed byHansenula anomala, Saccharomyces carlsbergensis andSaccharomyces cerevisiae. The yield of phenylacetylcarbinol in these cases was between 46.0% and 51.5 weight% (calculated on added benzaldehyde). During fementation with a higher benzaldehyde concentration,Saccharomyces carlsbergensis utilized 70% aldehyde for the formation of phenylacetylcarbinol while the rest was mostly reduced to benzylalcohol. Phenylacetylcarbinol was estimated after extraction of the fermentation medium with ether polarographically and polarimetrically, benzaldehyde was estimated polarographically directly in the medium.