Microbiology Session
Gudrun J Vogeser, PIKA Weihenstephan GmbH, Bavaria, Germany
ABSTRACT: Microbiological analyses are well established in
breweries’ routine control, but mostly are not relevant to make a
decision—the results either come out too late or they are too
indifferent to be of practical use, in the worst case they are both.
Fast detection methods including polymerase chain reaction (PCR) are
continuously being devised. With improvements in instrumentation and
sample handling for PCR analysis, this method is spreading into
laboratories for daily production control. The basic thought behind use
of PCR is to gain better and earlier knowledge about microbial process
contamination due to the considerably lower detection limits of PCR
compared with conventional enrichment methods. Beginners in using PCR in
microbiology keep their focus on the gain of time due to the shorter
duration of pre-enrichment. This study shows applications of PCR and
results from routine brewery analyses comparing traditional enrichment
methods with results from PCR. Based on case studies it is demonstrated
that not only the detection limit factor is important—especially for
troubleshooting the precision and specificity of this method is
unbeatable. Some contaminations were only detected due to PCR, remaining
invisible with the traditional enrichment methods. A major benefit can
be drawn from PCR results if sampling within the process line is
rethought and adjusted to the new method; fewer samples taken at other
time points in the process line resulted in the most effective output.
Gudrun
Vogeser received a diploma in microbiology from Eberhard Karls
University in Tuebingen, Germany. Her first job was at the Technical
University of Munich, Germany, where she finished her Ph.D. thesis in
1992. She was then employed as a scientist at the Chair of Brewing
Technology at TU Munich-Weihenstephan, where she examined the use of
molecular biology methods, mainly PCR, to detect and analyze beer
spoiling microorganisms. In 2000 she founded PIKA Weihenstephan,
Pfaffenhofen, Germany, a company that specializes in brewery and
beverage microbiology, where she is working as managing partner. Gudrun
is a founding member and since 2009 chair of the European Brewery
Convention (EBC) Microbiology Sub-committee and an ASBC member.
VIEW PRESENTATION 179
