Fraunhofer IME Master Class - Master Thesis offer at Fraunhofer IME in Aachen, in the Department Bioprocess engineering
Title: Purification of E. coli host cell proteins and their chromatographic characterization

Escherichia coli is a very common host for the expression of recombinant proteins. Most proteins are expressed intracellular and are mixed with host cell proteins (HCPs) after cell lysis. Therefore the removal of HCPs is crucial for purification. Different approaches exist to simplify purification such as affinity chromatography, heat or pH precipitation but these approaches are not applicable for all target proteins. Development of classical chromatography methods like ion exchange chromatography or hydrophobic interaction chromatography takes allot of effort and time. In order to reduce the number of experiments, we want to set-up a model for elution prediction. Part of this model is the steric mass action (SMA) model, which describes multicomponent protein-salt equilibria in ion-exchange systems, facilitating predictions about adsorption and desorption reactions

The student accepted for the project/thesis described above will have to develop a purification strategy for at least one host cell protein (HCP) from E. coli extract in sufficient amounts for SMA parameter determination (500 mg). To do so, the student will have to cultivate E. coli cells in shake flasks and a fermenter. Then extract, clarify and purify HCPs from E. coli cells, analyze them by SDS-PAGE, capillary gel electrophoresis, Bradford assay and additional protein quantification methods. The SMA parameter should be determined for at least 3 different anion exchange columns at pH 7.0 and 8.0.

Laboratory skills
(S)He has good basic knowledge in biochemistry and bioengineering and is willing to gain more insights into the issues faced by today’s plant and pharmaceutical biotechnology. At least basic experience in downstream processing is mandatory for a successful application.

Language skills
Fluent english and/or german

Computer skills
Excel and Powerpoint

Ealiest starting date 01.06.2021; expected Duration (months): > 6

Supervisor contact information
Name: Catherine Bernau
Phone: +49 241 6085-35001

In case of identical qualifications preference will be given to severely disabled candidates.
We would like to point out that the chosen job title also includes the third gender.
The Fraunhofer-Gesellschaft emphasises gender-independent professional equality.
Job Reference: IME-MB-2021-8 Closing Date: 30.06.2021