Bioprocess Engineering
6th BioProScale Symposium 2021

6th BioProScale Symposium

The 6th BioProScale Symposium took place virtually from 29.03. to 31.03.2021 Organized by the the chair of Bioprocess Engineering, the Bio-PAT Network and the IfGB. It was a great experience for us. We thank all contributors, participants, and sponsors. The restrictions of the Corona pandemic have presented us with special challenges. However, our presenters were able to overcome it and we have seen exciting presentations and posters. 

Over the three days, a total of 46 excellent lectures were held in the two sessons by representatives from industry and academia. The exciting virtual exhibitions of our ten sponsors and the 32 interesting posters rounded off the conference program. In the specially set up video chat area, lively discussions were held, there was an opportunity to get to know each other and to deepen the topics of the lectures. Some participants took advantage of this opportunity to stay up late into the night.

For all participants, all content of the 6th BioProScale Symposium will be available for rewatch until 6.04.21.

MDPI Lecture Award

The first MDPI Lecture Award went to Björn Gutschmann (Technische Universtiät Berlin) and Thomas Schiewe (Universität Potsdam / innoFSPEC, Germany) for their presentation In-line application of photon density wave spectroscopy as a PAT sensor in high cell-density bioprocesses: Monitoring of E. coli growth and PHA formation in R. eutropha.

A very good second place went to Sarah Täuber For the presentation entitled: Dynamic microfluidic single-cellcultivation: Growth of Corynebacterium glutamicum at fluctuating environmental conditions
In third place, the Scientific Advisory Board voted for Phuong Ho for the presentation entitled: Reproducingdynamicenvironment in microfluidic single-cellcultivationbased on computationallifelineanalysis

Eppendorf Poster Award

The Eppendorf Poster Award went to Mr. Amin Javidanbardan for the poster entitled: Rapidandcost-effective fabrication ofmicrochromatography integrated with microelectrode impedance sensor

The Scientific Advisory Board evaluated the posters of Jian Li (Cell-free biosynthesis of the nonribosomal peptide antibiotic valinomycin) and Tobias Höing (Cultured meat production in a 2D rocking bioreactor) with the second and third place, respectively. Congratulations to all winners.


MDPI Lecture Awards Winner Abstracts

In-line application of photon density wave spectroscopy as a PAT sensor in high cell-density bioprocesses: Monitoring of E. coli growth and PHA formation in R. eutropha

Björn Gutschmann1, Thomas Schiewe1,2,3, Marvin Münzberg2, Peter Neubauer1, Roland Hass3, Sebastian L. Riedel1
1Technische Universität Berlin, Chair of Bioprocess Engineering, Ackerstraße 76, 13355 Berlin, Germany
2innoFSPEC, University of Potsdam, Am Mühlenberg 3, 14476 Potsdam, Germany
3PDW Analytics GmbH, Geiselbergstr. 4, 14476 Potsdam, Germany 

A cost-efficient production process often involves high-cell-density cultivations, which represent challenging surroundings for optical process analytical technologies, due to signal saturation effects and probe fouling. An accurate process monitoring, and control strategy is a key concern for industrial bioprocesses. Addressing this issue, the integration of photon density wave (PDW) spectroscopy into highly turbid multiphase systems enables a novel approach for optical process monitoring. It allows for independent quantification of absorption and scattering properties by measuring the optical coefficients µa and µs’ while being suitable for highest particle concentrations (i.e. >40 vol%) in stirred or flowing systems [1, 2]. This contribution shows the application of a fully autoclavable in-line PDW spectroscopy probe during high-cell-density fed-batch cultivations. Results from Escherichia coli cultivations at 3.7-L scale show excellent correlations between the reduced scattering coefficient µs’ and biomass concentrations up to 76 g L-1. The results will be discussed in comparison to multiple established analytical methods. Additionally, for the first time polyhydroxyalkanoate (PHA) biopolymers formation and growth during cultivations of Ralstonia eutropha, was monitored in-line, simultaneously by separation of absorption and scattering properties using the PDW technology. Results of highcell-density fed-batch cultivations at 6.7-L scale with rapeseed oil [3] and the adaption to waste animal fats will be presented.

1. Bressel, L., Hass, R. and Reich, O. (2013) Particle sizing in highly turbid dispersions by Photon Density Wave spectroscopy. JQRST. 126: 122-129.
2. Hass, R., Munzke, D., Ruiz, S.V., Tippmann, J. and Reich, O. (2015) Optical monitoring of chemical processes in turbid biogenic liquid dispersions by Photon Density Wave spectroscopy. Anal Bioanal Chem. 407: 2791-802.
3. Gutschmann, B., Schiewe, T., Weiske, M.T., Neubauer, P., Hass, R. and Riedel, S.L. (2019) In-Line monitoring of polyhydroxyalkanoate (PHA) production during high-cell-density plant oil cultivations using Photon Density Wave Spectroscopy. Bioengineering. 6: 85.

Dynamic microfluidic single-cell cultivation: Growth of Corynebacterium glutamicum at fluctuating environmental conditions

Sarah Täuber1, Luisa Blöbaum1, and Alexander Grünberger1
1Multiscale Bioengineering, Technical Faculty, Bielefeld University, Bielefeld, Germany

In large-scale bioreactors, different gradients occur, which lead to a fluctuating supply of oxygen, nutrients and other process parameters that strongly influence the growth and production behaviour of the microbial strains and endanger the success of the scale-up [1]. Scale-down experiments are an established tool to investigate the growth and production related effects of industrial-scale gradients on microorganisms using lab-scale fermenters [2]. However, traditional scale-down approaches are bulk measurements and cannot provide the direct answer to how cells are affected by gradients on a single-cell level [3]. Novel analytical methods need therefore to be developed [4]. In this contribution, we introduce a microfluidic single-cell workflow for the cultivation of microbial cells under dynamic environmental conditions [5]. This system allows oscillation between different environmental input parameters e.g., between pH values or carbon sources. We give an overview into the technology and show how oscillating environmental conditions (here C source and pH value) affect the cellular physiology. In a first study, we cultivated C. glutamicum under oscillating medium conditions (medium rich and buffer) with different oscillation frequencies ranging from hours to seconds intervals [5]. A significant difference within the overall growth behaviour was observed at different oscillations frequencies. Oscillations time between 5 and 15 minutes significantly affect the overall growth rate. At higher oscillations frequencies growth was not impaired significantly. In a second study, we investigated the growth behaviour of C. glutamicum under specific pH oscillations that varied in their pH amplitude and frequency [6]. pH oscillations between discrete pH units decreased the overall growth rate. The decrease was dependent on the stress pH values (e.g., pH=5) and the ratio of pH stress phases to regeneration phase at pH=7. Latest results, hypothesis regarding the observed growth pattern and potential application will be shown. Our results show that the concept of dynamic microfluidic single-cell cultivation has a high potential to investigate cellular physiology at dynamic environmental conditions. This paves the way for an improved understanding of how environmental conditions shape metabolic heterogeneity and thus the cellular response within growth and production upon nutrient and pH gradients within large-scale bioprocesses, often referred as lifeline. In future it is essential to validate the technology with conventional scale-down approaches to further optimize the technology towards novel single-cell scale-down reactors.

1. Takors, R. (2012) Scale-up of microbial processes: impacts, tools and open questions. Journal of biotechnology, 160: 3–9.
2. Delvigne, F. and Noorman, H. (2017) Scale-up/Scale-down of microbial bioprocesses: a modern light on an old issue. Microbial biotechnology, 10: 685–687.
3. Lemoine, A., Maya Martinez-Iturralde, N., Spann, R., Neubauer, P. and Junne, S. (2015) Response of Corynebacterium glutamicum exposed to oscillating cultivation conditions in a two- and a novel three-compartment scale-down bioreactor. Biotechnology and bioengineering, 112: 1220–1231.
4. Grünberger, A., Wiechert, W. and Kohlheyer D. (2014) Single-cell microfluidics: opportunity for bioprocess development. Current opinion in biotechnology, 29: 15-23.

Reproducing dynamic environment in microfluidic single-cell cultivation based on computational lifeline analysis

Phuong Ho1, Sarah Täuber2, Alexander Grünberger2, Eric von Lieres1
1Forschungszentrum Jülich, IBG-1: Biotechnology, Wilhelm-Johnen-Str. 1, 52428 Jülich, Germany
2Universität Bielefeld, Multiscale Bioengineering, Universitätsstraße 25, 33615 Bielefeld

The biotechnological production of valuable substances is typically complicated by the loss of microbial performance upon scale-up [1-3]. This challenge is mainly caused by discrepancies between homogeneous environmental conditions at laboratory scale, where organisms are optimized, and inhomogeneous conditions in large-scale bioreactors, where the production takes place. To improve strain selection and process development, it is thus of major interest to characterize these fluctuating conditions at large scales and investigate their impact on microbial cells. In this contribution, we will demonstrate the high potential of dynamic microfluidic single-cell cultivation combined with computational fluid dynamics (CFD) simulation of large-scale bioreactors. CFD simulations of a 300 L bioreactor were applied to characterize environmental conditions in large-scale bioreactors. So-called lifelines were determined by simulating multiphase turbulent flow and mass transport combined with particle tracing. Glucose availability experienced by the microorganism Corynebacterium glutamicum was traced. Resulting lifelines were discretized into low, medium and high glucose availability regimes. Discretized lifelines were used as feeding profiles of a dynamic microfluidic single-cell cultivation (dMSCC) system to investigate how the fluctuating glucose concentration affects cellular physiology and colony growth rate. The presented approach paves the way for an improved understanding of how the cellular lifelines of large-scale bioreactors influence the cellular response within growth and production. It also provides insights into how to understand the conditions in large-scale bioreactors from the view of a microorganism and the dependence of cell wellbeing on the observed conditions.

1. Oosterhuis N.M.G. and Kossen N.W.F. (1984) Dissolved-oxygen concentration profiles in a production-scale bioreactor. Biotechnol. Bioeng. 26: 546-550.
2. Larsson G. and Enfors S.O. (1985) Influence of oxygen starvation on the respiratory capacity of Penicillium chrysogenum. Appl. Microbiol. Biotechnol. 21: 228-233.
3. Enfors S.O., Jahic M., Rozkov A., et al. (2001) Physiological responses to mixing in large scale bioreactors. Journal Biotechnol. 85: 175- 185.