Open AccessYeast pyruvate decarboxylases: variation in biocatalytic characteristics for ( R )‐phenylacetylcarbinol production
Author(s) -
Gunawan Cindy,
Satianegara Gernalia,
Chen Allen K.,
Breuer Michael,
Hauer Bernhard,
Rogers Peter L.,
Rosche Bettina
Publication year - 2007
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2006.00138.x
Subject(s) - acetoin , benzaldehyde , pyruvate decarboxylase , yeast , candida tropicalis , biology , biochemistry , aqueous solution , food science , chemistry , enzyme , organic chemistry , fermentation , catalysis , alcohol dehydrogenase
Based on previous studies, Candida utilis pyruvate decarboxylase (PDC) proved to be a stable and high productivity enzyme for the production ( R )‐phenylacetylcarbinol (PAC), a pharmaceutical precursor. However, a portion of the substrate pyruvate was lost to by‐product formation. To identify a source of PDC which might overcome this problem, strains of four yeasts – C. utilis , Candida tropicalis , Saccharomyces cerevisiae and Kluyveromyces marxianus – were investigated for their PDC biocatalytic properties. Biotransformations were conducted with benzaldehyde and pyruvate as substrates and three experimental systems were employed (in the order of increasing benzaldehyde concentrations): (I) aqueous (soluble benzaldehyde), (II) aqueous/benzaldehyde emulsion, and (III) aqueous/octanol‐benzaldehyde emulsion. Although C. utilis PDC resulted in the highest concentrations of PAC and was the most stable enzyme, C. tropicalis PDC was associated with the lowest acetoin formation. For example, in system (III) the ratio of PAC over acetoin was 35 g g −1 for C. tropicalis PDC and 9.2 g g −1 for C. utilis PDC. The study thereby opens up the potential to design a PDC with both high productivity and high yield characteristics.