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Background  The yeast amino acid catabolism plays an important role in flavour generation since higher alcohols and acetate esters, amino acid catabolism end products, are key components of overall flavour and aroma in fermented products. Comparative studies have shown that other  Saccharomyces  species, such as  S. kudriavzevii , differ during the production of aroma-active higher alcohols and their esters compared to  S. cerevisiae .    Results  In this study, we performed a comparative analysis of the enzymes involved in the amino acid catabolism of  S. kudriavzevii  with their potential to improve the flavour production capacity of  S. cerevisiae . In silico screening, based on the severity of amino acid substitutions evaluated by Grantham matrix, revealed four candidates, of which  S. kudriavzevii  Aro10p (SkAro10p) had the highest score. The analysis of higher alcohols and esters produced by  S. cerevisiae  then revealed enhanced formation of isobutanol, isoamyl alcohol and their esters when endogenous  ARO10  was replaced with  ARO10  from  S. kudriavzevii.  Also, significant differences in the aroma profile were found in fermentations of synthetic wine must. Substrate specificities of SkAro10p were compared with those of  S. cerevisiae  Aro10p (ScAro10p) by their expression in a 2-keto acid decarboxylase-null  S. cerevisiae  strain. Unlike the cell extracts with expressed ScAro10p which showed greater activity for phenylpyruvate, which suggests this phenylalanine-derivative to be the preferred substrate, the decarboxylation activities measured in the cell extracts with SkAro10p ranged with all the tested substrates at the same level. The activities of SkAro10p towards substrates (except phenylpyruvate) were higher than of those for ScAro10p.    Conclusions  The results indicate that the amino acid variations observed between the orthologues decarboxylases encoded by  SkARO10  and  ScARO10  could be the reason for the distinct enzyme properties, which possibly lead to the enhanced production of several flavour compounds. The knowledge on the important enzyme involved in higher alcohols biosynthesis by  S. kudriavzevii  could be of scientific as well as of applied interest.    Electronic supplementary material  The online version of this article (doi:10.1186/s12934-016-0449-z) contains supplementary material, which is available to authorized users.

microbial cell factories

Characterisation of the broad substrate specificity 2-keto acid decarboxylase Aro10p of Saccharomyces kudriavzevii and its implication in aroma development