Yeast and Fermentation Session
Anita Van Landschoot, University College Ghent, Ghent, Belgium
Co-author(s): Sylvie Vandoorne and Dana Vanderputten, University
College Ghent, Ghent, Belgium; Gary Prescott, BioTek Instruments Inc.,
Luzern, Switzerland
ABSTRACT: Saccharomyces strains are industrially
important yeasts in the production of many beverages. The ability to
obtain the desired product reliably and repeatedly in the same amounts
requires careful monitoring of not only the material inputs, but also
the growth of the yeast strain during propagation or
hydration/revitalization, in the case dried yeast, that is used for the
fermentation process. This often requires monitoring of the growth of
these strains under various conditions to optimize industrial
conditions. The Synergy H1 hybrid multi-mode microplate reader was used
to provide temperature control, suspension agitation, and monitor
cellular yeast growth using light scattering in 96-well microplates at
600 nm. Measurements were made every 2 min, and data were collected
using Gen5 data analysis software. The system was used to explore the
optimum conditions for propagation and hydration/revitalization of 13
industrial yeast strains. These Saccharomyces yeasts were used to
study the effect of temperature, pH, and density of industrial media
(wort or must of white grapes) on yeast growth/biomass production.
Lowering the pH of the wort to an industrially acceptable value of 4.8
had almost no effect on yeast growth for the different densities of the
wort. Lowering the density of the wort or must to about 10°P extract of
malt or grapes always had a positive effect on yeast growth. This proved
that such medium contains sufficient nutrients for the industrially
necessary yeast growth during propagation or hydration/revitalization.
If it is industrially relevant, a higher yeast growth temperature can be
used. At 30°C the same final cell number can be obtained in half the
time compared to room temperature. The final conclusion is that the
Synergy H1 microplate reader is a useful high throughput system to
screen for optimal industrial growth/revitalization conditions for
industrial yeasts. The system has also been tested for fast screening of
yeast fermentation conditions.
Anita Van Landschoot is a
professor at University College Ghent and Ghent University and lecturer
in brewing technology and industrial microbiology. The research of
Anita’s group is related to applications of microbial and enzymatic
biotechnology: industrial yeast starter cultures, microbial
contaminants, microbial populations, antibacterial activity, industrial
fermentation processes, glycobiology, and isolation and characterization
of microorganisms and some enzymes. The group has the technology and
know-how for extraction and fermentation of biomass to ethanol and for
the brewing of most Belgian beer types. Most of the research is done in
collaboration with industry. The brewing lab represents the oldest
Belgian brewing institute.
VIEW PRESENTATION 242
