Research Assistant and Doctoral Candidate
Tobias Köllen, M.Sc.
Research Assistant and Doctoral Candidate
Phone: +49 (0) 89 289-54209
Mail: tobias.koellen@tum.de
TUM Catalytic Research Center
Ernst-Otto-Fischer Straße 1
Germany, 85748 Garching
Raum 2018
Vita
Curriculum
- Since 12/2021: Doctorate at the Chair of Chemistry of Biogenic Raw Materials
- 2018-2021: Master’s degree in Molecular Biotechnology,Technical University Munich
- Master thesis at the Chair of Chemistry of Biogenic Resources: “Development of enzymaticassays for the identification of novel enzymes enzymes in microfluidics-based in vitro transcription transcription-translation systems”.
- 2014-2018: Bachelor’s degree in molecular biotechnology, Technical University of Munich
- Bachelor thesis at the Chair of Microbiology: “Directed mutagenesis of a GH10 xylanase from Clostridium stercorarium for thermostabilisation”.
Research focus:
Acceleration of enzyme engineering through application of cell free protein expression platforms
Location: Garching lab
It is my goal to accelerate enzyme engineering through the application of cell free protein synthesis platforms (CFPS). By making use of CFPS, several challenges in enzyme engineering associated with heterologous gene expression can be overcome. First, CFPS does not require the transformation of cells with circular DNA molecules. Therefore, transformation efficiency is not the bottleneck that defines enzyme variant library size. Instead, the throughput of the screening procedure becomes limiting. In addition to this, CFPS allows for the direct expression of linear DNA templates and therefore greatly reduces the bias and effort of variant library construction. Further, the open nature of the system enables the addition of factors without the need to cross a cellular membrane, thereby improving control over expression conditions and cofactor loading. In order to facilitate ultra-high throughput screening, I employ a droplet microfluidic device capable of sorting water in oil emulsion droplets at a rate of 1,000 droplets per second. Single DNA molecules are encapsulated into picoliter-sized droplets alongside a CFPS reaction mix and assay reagents. In order to produce a measurable result, each DNA molecule is amplified within the droplet and expressed in concert with a biochemical assay reaction. Droplets that display high signal intensities are sorted and analyzed to inform further enzyme engineering efforts. This workflow allows for the exploration of vast sequence-function spaces only accessible through cell free protein synthesis