Stijn Mertens (1); (1) KU Leuven/VIB, Heverlee, Belgium
Technical Session 3: Yeast Biotechnology
Sunday, August 14 • 9:45–11:30 a.m.
Plaza Building, Concourse Level, Governor’s Square 15
Despite the enormous diversity in ale yeasts, the diversity of yeasts used in the lager beer industry (Saccharomyces pastorianus)
is very limited. In fact, only two archetypes of lager yeasts are
currently used in breweries, which are the result of one or two
independent interspecies hybridization events, presumably originating
from the 15th or 16th century, between the traditional brewer’s yeast Saccharomyces cerevisiae and Saccharomyces eubayanus.
This confined genetic (and as a consequence phenotypic) diversity of
lager yeasts is reflected in the relatively limited influence of the
yeast strain on the aroma profile of lager beers. Because of the
increased importance of product innovation to breweries, new lager
yeasts with a diverse aroma production opens the window to re-enforce
their position on the lager beer market. In this study, we generated a
large set of new lager yeasts by crossing carefully selected S. cerevisiae and cold tolerant Saccharomyces species like S. eubayanus, S. kudriavzevii and S. mikatae.
We obtained more than 250 new and unique lager strains. Next, these
newly developed hybrids were genetically stabilized and screened for
their fermentation capacity and aroma production in lager beer
fermentations and their temperature tolerance. The applied approach
resulted in a large set of new lager yeasts that display an enormous
phenotypic diversity, with different lineages able to produce a whole
new spectrum of lager beers with diverse aroma profiles. Moreover, these
strains are directly applicable in industry, since the experimental
procedure doesn’t rely on genetic modification.
Stijn Mertens received a B.S. degree in bioscience engineering
from the University of Leuven, Belgium, in 2011 and an M.S. degree in
bioscience engineering, major cell and gene technology, minor industrial
microbiology, from the same university in 2013. He did his master
thesis work in the VIB Laboratory for Systems Biology, led by Prof.
Kevin Verstrepen, in 2012-2013, for which he was awarded the annual M.S.
thesis prize of the Royal Society of Brewing Schools. He later joined
the lab as a Ph.D. student.