J. BIERING (1), A. Bockisch (2), R. Folz (1), R. Pahl (1), S. Junne
(2), P. Neubauer (2); (1) VLB-Berlin, Berlin, Germany; (2) TU-Berlin,
Berlin, Germany
Poster
Mixing in fermentation processes is only supported through convection,
driven by rising bubbles of carbon dioxide and temperature gradients.
Hence, the occurrence of gradients in large-scale processes is likely
and has been described by various authors (Nienow, A. W. Biotechnol. J., 2011; Schuch, C., Brauwelt, 1996). The distribution of oxygen, CO2, temperature, and cell density is uneven (Annemüller, G., and Manger, H. J. VLB Berlin; Schuch, C., Brauwelt, 1996; Schuch, C., Brauwelt,
1996). This can influence the formation of gradients concerning other
parameters (e.g., redox potential, pH), as well as the formation and
degradation of metabolites. Off-line samples taken or data from at-line
monitoring devices installed at one point on the tank wall are not
representative of the whole process since different positions are not
regarded. In order to increase the understanding of gradients, their
impact on a process, and their importance for process design,
miniaturized multiposition sensors and a device for the submersion of
commercial sensors have been developed for in-line and real-time
monitoring. Further studies on cell metabolism, morphology, and
physiology have been performed in order to allow an improved
understanding of the impact of oscillating conditions on the cell. A
sampling system for the collection of samples at any point in
large-scale tanks for off-line analysis will be developed. In brewing
processes with a volume over 1,000 L, gradients concerning redox
potential, temperature, and pH can be estimated, especially in the onset
of fermentation. In processes of smaller volume (200 L), differences
concerning cell physiology and concentration of metabolites can be
observed between different heights since sampling at different ports in
the tank is possible. The correlation of the in-line and off-line data
provided information about the impact of several parameters and their
gradients on cells and the whole process, leading to an improved process
control. A submersible system for large-scale fermenters in order to
measure different parameters at the same time and locally independent
does not exist yet. With the developed miniaturized system,
multiposition and multiparameter measurements can be performed,
providing in-line data that can be visualized in real time. At the
moment, at-line monitoring of a brewing process that takes place only at
one position on the tank wall does not provide sufficient process
control. The identification of critical reactor zones and their
investigation by in-line monitoring will allow fast detection of
disturbances, while targets for process optimization can be identified.
Hence, processes can be improved concerning time, energy efficiency, and
costs.
Jan Biering was born in 1976. From 1995 to 1997 Jan apprenticed as a
brewer and maltster at Reichelbräu Kulmbach. From 1997 to 2003 Jan
studied brewing technology at the TU-Berlin. From 2003 to 2011 Jan was
brewmaster and plant manager at Schlossbrauerei Schwarzbach. Since 2012
Jan has worked at VLB Berlin.
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