TY - JOUR
T1 - Inheritance of brewing-relevant phenotypes in constructed Saccharomyces cerevisiae x Saccharomyces eubayanus hybrids
AU - Krogerus, Kristoffer
AU - Seppänen-Laakso, Tuulikki
AU - Castillo, Sandra
AU - Gibson, Brian
N1 - Funding Information:
This work was supported by the Alfred Kordelin Foundation, Svenska Kultur‑ fonden ‑ The Swedish Cultural Foundation in Finland, PBL Brewing Laboratory, and the Academy of Finland (Academy Project 276480).
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/4/21
Y1 - 2017/4/21
N2 - Background: Interspecific hybridization has proven to be
a potentially valuable technique for generating de novo
lager yeast strains that possess diverse and improved
traits compared to their parent strains. To further
enhance the value of hybridization for strain
development, it would be desirable to combine phenotypic
traits from more than two parent strains, as well as
remove unwanted traits from hybrids. One such trait, that
has limited the industrial use of de novo lager yeast
hybrids, is their inherent tendency to produce phenolic
off-flavours; an undesirable trait inherited from the
Saccharomyces eubayanus parent. Trait removal and the
addition of traits from a third strain could be achieved
through sporulation and meiotic recombination or further
mating. However, interspecies hybrids tend to be sterile,
which impedes this opportunity. Results:
Here we generated a set of five hybrids from three
different parent strains, two of which contained DNA from
all three parent strains. These hybrids were constructed
with fertile allotetraploid intermediates, which were
capable of efficient sporulation. We used these eight
brewing strains to examine two brewing-relevant
phenotypes: stress tolerance and phenolic off-flavour
formation. Lipidomics and multivariate analysis revealed
links between several lipid species and the ability to
ferment in low temperatures and high ethanol
concentrations. Unsaturated fatty acids, such as oleic
acid, and ergosterol were shown to positively influence
growth at high ethanol concentrations. The ability to
produce phenolic off-flavours was also successfully
removed from one of the hybrids, Hybrid T2, through
meiotic segregation. The potential application of these
strains in industrial fermentations was demonstrated in
wort fermentations, which revealed that the meiotic
segregant Hybrid T2 not only didn't produce any phenolic
off-flavours, but also reached the highest ethanol
concentration and consumed the most maltotriose.
Conclusions: Our study demonstrates the possibility of
constructing complex yeast hybrids that possess traits
that are relevant to industrial lager beer fermentation
and that are derived from several parent strains. Yeast
lipid composition was also shown to have a central role
in determining ethanol and cold tolerance in brewing
strains.
AB - Background: Interspecific hybridization has proven to be
a potentially valuable technique for generating de novo
lager yeast strains that possess diverse and improved
traits compared to their parent strains. To further
enhance the value of hybridization for strain
development, it would be desirable to combine phenotypic
traits from more than two parent strains, as well as
remove unwanted traits from hybrids. One such trait, that
has limited the industrial use of de novo lager yeast
hybrids, is their inherent tendency to produce phenolic
off-flavours; an undesirable trait inherited from the
Saccharomyces eubayanus parent. Trait removal and the
addition of traits from a third strain could be achieved
through sporulation and meiotic recombination or further
mating. However, interspecies hybrids tend to be sterile,
which impedes this opportunity. Results:
Here we generated a set of five hybrids from three
different parent strains, two of which contained DNA from
all three parent strains. These hybrids were constructed
with fertile allotetraploid intermediates, which were
capable of efficient sporulation. We used these eight
brewing strains to examine two brewing-relevant
phenotypes: stress tolerance and phenolic off-flavour
formation. Lipidomics and multivariate analysis revealed
links between several lipid species and the ability to
ferment in low temperatures and high ethanol
concentrations. Unsaturated fatty acids, such as oleic
acid, and ergosterol were shown to positively influence
growth at high ethanol concentrations. The ability to
produce phenolic off-flavours was also successfully
removed from one of the hybrids, Hybrid T2, through
meiotic segregation. The potential application of these
strains in industrial fermentations was demonstrated in
wort fermentations, which revealed that the meiotic
segregant Hybrid T2 not only didn't produce any phenolic
off-flavours, but also reached the highest ethanol
concentration and consumed the most maltotriose.
Conclusions: Our study demonstrates the possibility of
constructing complex yeast hybrids that possess traits
that are relevant to industrial lager beer fermentation
and that are derived from several parent strains. Yeast
lipid composition was also shown to have a central role
in determining ethanol and cold tolerance in brewing
strains.
KW - yeast
KW - beer
KW - rare mating
KW - lipid
KW - fatty acid
KW - phenolic off-flavour
KW - aroma
KW - Yeast
KW - Lipid
UR - http://www.scopus.com/inward/record.url?scp=85018501297&partnerID=8YFLogxK
U2 - 10.1186/s12934-017-0679-8
DO - 10.1186/s12934-017-0679-8
M3 - Article
SN - 1475-2859
VL - 16
JO - Microbial Cell Factories
JF - Microbial Cell Factories
IS - 1
M1 - 66
ER -