(Poster_A0_JTdBiotechnologen2013

Online-Ethanol and Online-Methanol
Measurements in Fermentation Processes
www.trace.de
INTRODUCTION
Michael Hartlep and Wolfgang Künnecke
Ethanol and methanol are products of various microorganisms. Depending on the process they can
be main product, by-product, or can be used as inducer. In a lot of processes it is important to monitor
the amount of ethanol or methanol in order to know the end point of the fermentation or to avoid a
toxic concentration inside the fermentation broth. For some organisms methanol is used as an
inducer, where the concentration must be controlled in a very tight range. BioPAT® Trace is a new online analyzer for measuring methanol and ethanol in fermentation processes.
BioPAT® Trace on-line analyzer
Enzyme reactor
BioPAT® Trace is an on-line analyzer for measuring
ethanol or methanol (Figure 1). Both substances can be
detected continuously.
The enzymatic bioreactor has
life time of 5000 measurements
or 14 days.
The reactor is very small,
reusable, and easy to connect
with a Luer connector (Figure 2).
TRACE Analytics GmbH
Richard-Wagner-Straße 1-2 | 38106 Braunschweig (Germany)
Holger Penders
Sanofi-Aventis Deutschland GmbH
Industriepark Hoechst | 65926 Frankfurt am Main (Germany)
Ethanol monitoring in an
industrial fermentation process
Figure 2. Enzyme reactor
A fed-batch fermentation of a recombinant yeast was
performed. This process run over 70 hours. The yeast was
cultivated on a glucose medium.
During the first 20 hours ethanol was produced and
consumed. After this period the ethanol concentration
stayed at a very low level near 0 g/L. With the BioPAT®
Trace it was possible to monitor this trend (dark green line
in Figure 5).
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Analytical performance
Enzymatic reaction and detection
In the presence of oxygen the immobilized enzyme
alcoholoxidase (AOD) catalyses the transformation of
alcohol (e.g. methanol or ethanol) to the corresponding
aldehyde and hydrogen peroxide. The alcohol content is
measured indirectly on a platinum electrode via the
formed hydrogen peroxide, which is oxidized to water and
oxygen. In an amperometric measurement the electrical
current is proportional to the amount of oxidized alcohol.
Methanol
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CONCLUSION
The BioPAT® TRACE is a new online alcohol
analyzer for measuring ethanol and methanol.
During an industrial fermentation process it was
demonstrated that the dynamic profile of ethanol
production and consumption can be reliably
monitored with the BioPAT® Trace analyzer.
15
4
0
0
10
10
20
30
Time [h]
40
50
60
Figure 5. Ethanol concentration in a fermentation run with
a recombinant yeast.
5
Data points
graph of reference values
Linear (Data points)
0
0
5
10
15
reference value [g/L]
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Figure 3. Linearity of methanol measurements
The ethanol concentration data from the BioPAT® Trace
were proven with offline data (yellow points in Figure 5)
and with online data from another alcohol analyzer (brown
line in Figure 5).
It was possible to show the robustness of the process and
of the BioPAT® Trace in three fermentation runs (Figure 6).
Ethanol
40
actual value [g/L]
6
2
y = 0,9713x + 0,0448
R² = 0,9984
y = 0,9833x + 0,1658
R² = 0,9988
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Safe and economic operations
Low installation size and less
maintenance effort
Assays of ethanol and methanol
Disposable consumables (tubing set,
sensor, reactors and transport solution)
Enzyme reactors with
long-term stability and low drift
No sample volume required
Connection to different fermenter types
Ethanol [g/L]
The range of methanol concentration is 0.5 - 20 g/L and
the range of ethanol concentration is 1 - 40 g/L. The
measurement frequency is about 25 per hour. Because of
the internal temperature correction coefficient a
temperature range from 15°C to 25°C is possible.
ProcessTRACE online analyzer
8
10
fermentation 1
30
fermentation 2
fermentation 3
8
25
20
15
10
Data points
graph of reference values
Linear (Data points)
5
0
0
5
10 15 20 25 30
reference value [g/L]
Figure 4. Linearity of ethanol measurements
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40
Ethanol [g/L]
Trace on-line analyzer
actual value [g/L]
Figure 1.
BioPAT®
BioPAT Trace online analyzer
Offline data (Selectra E)
The linearity of the measurements was proven by
changing the concentrations of methanol in the range
between 0 and 20 g/L (Figure 3) and by changing the
concentrations of ethanol in the range between 0 and
40 g/L (Figure 4).
6
4
2
0
0
5
10
15
Time [h]
20
Figure 6. Ethanol profiles of three fermentation runs.
Ethanol concentrations can be reliably monitored in
fermentation processes with the BioPAT® Trace.
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