Center for Applied ChemistryInstitute for Technical ChemistryCallinstr. 5 , 30167 Hannover

C. Wolff , L. Hilterhaus , M. Kisch , D. Kaufhold , F. Kopf , M. Hoffmann , S. Beutel , A. Liese , M. Schlüter and T. Scheper

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1Institute for Technical Chemistry, Leibniz University Hannover, Callinstr. 5, D-30167 Hannover

Institute of Technical Biocatalysis, Hamburg University of Technology, Denickestr. 15, D-21071 Hamburg Institut of Multiphase Flows, , Eißendorfer Str. 38, D-21073 Hamburg

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3 Hamburg University of Technology

Acknowledgements

Development and Testing of modular Hollow Fiber Bioreactors

IntroductionHollow fiber reactors offer a high potential in biotechnology. There are possible applications in the fields of biocatalysis, the cultivation of pro- and eukaryotes and the process integrated removal of products. This is possible by the continuous separation of products and retention of cells through the hollow fibers. Another option is the modification and functionalization of hollow fibers with specific receptors or ligands to bind products or remove interfering substances from the process.The DFG-Project “Modular Hollow Fiber Reactors under Consideration of Micro Scale Effects” works on the development, characterization and testing of such systems. Fig.1 Hollow Fiber Bioreactor Prototype

Fig. 2 Schematic set up of hollow fiber bioreactor for cultivation tasks

Fig. 3 Cultivation of Chlamydomonas reinhardtii

ConfigurationThe new developed prototype modular hollow fiber bioreactors are equipped with two different cylinders holding either 6 ceramic hollow fibers (0,2 µm) or 72 PES hollow fibers (80 kDa). The design allows the integration of additional types of fibers by replacement of the inner cylinder. The System is divided in the extra-capillary space (ECS) and the intra-capillary space (ICS). The Volume of the ICS can be adjusted to the demand of the process. A configuration of the System for cultivation tasks is shown in Fig. 2. The ICS and ECS circulate to provide a homogenous mixing of the system. The cells grow in the ECS and a reservoir for a feeding solution and accumulation of products is integrated in the ICS cycle. Both cycles can be accessed through septums. Several reactors can be operated simultaneously e.g. for process parameter screening.

Current WorkThe current work deals with the characterization of the new system in regard to

residence time, mass transport and mixing behavior. Furthermore procedures for

sterilization and preparation of the reactor system are established.

The micro-algae Chlamydomonas reinhardtii was used as model organism for

cultivation experiments in comparison to a shaking flask culture. Ceramic hollow

fibers were used for aeration in the reactor with humidified air to prevent the loss of

volume (Fig. 3). The culture grew up to a OD of 2,8 in comparison to cultures in 550

shaking flasks which grew to a OD of 2,2.550

OutlookTo obtain optimal process control fiber optical oxygen- and pH-sensors will be integrated in the system. An experiment to monitor product formation by ultrasonic measurement is in the pipeline. Furthermore cultivation experiments with other model organisms like will be performed and additional types of hollow fibers will be tested in cultivation experiments.

Escherichia.coli and Pleurotas.sapidus

Biocatalytic applications are in focus of the workgroup around Prof. Liese while the fluiddynamic characterization and optimization is the task of Prof. Schlüter´s workgroup at the TUHH.

This work was performed within the activities of the DFG working group “Micro Hollow Fiber Reactors under Consideration of Micro Scale Effects”.