Contribution of Eat1 and Other Alcohol Acyltransferases to Ester Production in Saccharomyces cerevisiae

• Published in: Frontiers in microbiology Vol. 9; p. 3202
• Main Authors: Kruis, Aleksander J, Gallone, Brigida, Jonker, Timo, Mars, Astrid E, van Rijswijck, Irma M H, Wolkers-Rooijackers, Judith C M, Smid, Eddy J, Steensels, Jan, Verstrepen, Kevin J, Kengen, Servé W M, van der Oost, John, Weusthuis, Ruud A
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 21.12.2018
• Subjects: AAT; alcohol acyltransferase; BacGen; BBP Bioconversion; Bioprocess Engineering; Bioprocestechnologie; Eat1p; ester; FBR Bioconversion; Food Microbiology; Food Microbiology Laboratory; Laboratorium Levensmiddelenmicrobiologie; Laboratorium voor Microbiologie; Leerstoelgroep Bioprocestechnologie; Levensmiddelenmicrobiologie; Microbiological Laboratory; Microbiologie; Microbiology; Saccharomyces cerevisiae; VLAG; WIMEK; yeast; alcohol acyltransferase; AAT; ester; Eat1p; Saccharomyces cerevisiae; wine; yeast
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2018.03202

Esters are essential for the flavor and aroma of fermented products, and are mainly produced by alcohol acyl transferases (AATs). A recently discovered AAT family named Eat (Ethanol acetyltransferase) contributes to ethyl acetate synthesis in yeast. However, its effect on the synthesis of other esters is unknown. In this study, the role of the Eat family in ester synthesis was compared to that of other AATs (Atf1p, Atf2p, Eht1p, and Eeb1p) and . A genomic study in a collection of industrial strains showed that variation of the primary sequence of the AATs did not correlate with ester production. Fifteen members of the family from nine yeast species were overexpressed in CEN.PK2-1D and were able to increase the production of acetate and propanoate esters. The role of Eat1p was then studied in more detail in CEN.PK2-1D by deleting in various combinations with other known AATs. Between 6 and 11 esters were produced under three cultivation conditions. Contrary to our expectations, a strain where all known AATs were disrupted could still produce, e.g., ethyl acetate and isoamyl acetate. This study has expanded our understanding of ester synthesis in yeast but also showed that some unknown ester-producing mechanisms still exist.