Title |
Molecular characterization of the Saccharomycopsis fibuligera ATF genes, encoding alcohol acetyltransferase for volatile acetate ester formation |
Author |
Hye Yun Moon1, Hyeon Jin Kim1, Ki Seung Kim1, Su Jin Yoo1, Dong Wook Lee1, Hee Je Shin1, Jeong Ah Seo2, and Hyun Ah Kang1* |
Address |
1Molecular Systems Biology Laboratory of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea, 2School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea |
Bibliography |
Journal of Microbiology, 59(6),598–608, 2021,
|
DOI |
10.1007/s12275-021-1159-8
|
Key Words |
Saccharomycopsis fibuligera, volatile flavor, acetate
esters, alcohol-O-acetyltransferases |
Abstract |
Aroma ester components produced by fermenting yeast cells
via alcohol acetyltransferase (AATase)-catalyzed intracellular
reactions are responsible for the fruity character of fermented
alcoholic beverages, such as beer and wine. Acetate esters
are reportedly produced at relatively high concentrations by
non-Saccharomyces species. Here, we identified 12 ATF orthologues
(SfATFs) encoding putative AATases, in the diploid
genome of Saccharomycopsis fibuligera KJJ81, an isolate from
wheat-based Nuruk in Korea. The identified SfATF proteins
(SfAtfp) display low sequence identities with S. cerevisiae
Atf1p (between 13.3 and 27.0%). All SfAtfp identified, except
SfAtf(A)4p and SfAtf(B)4p, contained the activation domain
(HXXXD) conserved in other Atf proteins. Culture supernatant
analysis using headspace gas chromatography mass spectrometry
confirmed that the recombinant S. cerevisiae strains
expressing SfAtf(A)2p, SfAtf(B)2p, and SfAtf(B)6p produced
high levels of isoamyl and phenethyl acetates. The volatile
aroma profiles generated by the SfAtf proteins were distinctive
from that of S. cerevisiae Atf1p, implying difference in
the substrate preference. Cellular localization analysis using
GFP fusion revealed the localization of SfAtf proteins proximal
to the lipid particles, consistent with the presence of amphipathic
helices at their N- and C-termini. This is the first
report that systematically characterizes the S. fibuligera ATF
genes encoding functional AATases responsible for acetate
ester formation using higher alcohols as substrate, demonstrating
their biotechnological potential for volatile ester production. |