Team:TU Eindhoven/Project

This year’s iGEM team of the Eindhoven University of Technology focuses on a fundamental problem in the application of genetically modified bacteria: bacteria are not suited for many environments. For example, local bacterial production of medicine has a promising future as a medical treatment, but the human immune system is still a big limiting factor for this new technology. Another field that would greatly benefit from more resilient bacteria is the bioreactor industry. Bacteria that can survive in high pressure and temperature environments can help increasing efficiency of reactors.

To create such resilient bacteria the 2014 team has designed a ‘plug and play’ system using copper free click chemistry to attach different chemical groups to create bio-layers on E. Coli cell membranes. Circularly permuted OmpX (CPX), an outer membrane protein, was mutated to contain an azido-functionalized unnatural amino acid. CPX functions as an anchor for any DBCO functionalized molecule to click onto. The polymers used in this project were designed to form hydrogels, which enables the bacteria to have antifouling properties.

With our team’s biomedical background in mind, an anti-fouling chemical layer for use in the human body was chosen to test the ‘plug and play’ system. An anti-fouling hydrogel has to have little to no interaction with the human immune system, thus preventing immune responses caused by the presence of bacteria. Dibenzocyclooctyne Polyethylene glycol 10kDa (DBCO-PEG 10kDa) was chosen as the molecule to click onto OmpX to form the hydrogel because it has good anti-fouling properties and the modular length allows for easy testing on a smaller scale.

In order to precisely control the hydrogel formation, microfluidic devices are used in which the conditions are optimal to form individually encapsulated cells. This way clustering of cells is prevented and the end product will be usable beads instead of large aggregated blobs.