Chemical Engineering/ CEMI Seminar

Carbon dioxide (CO₂) is a potent greenhouse gas that is a critical factor in global warming. At the same time atmospheric CO₂ is a cheap and ubiquitous carbon source. Yet, synthetic chemistry lacks suitable catalysts to functionalize atmospheric CO₂, emphasizing the need to understand and exploit the CO₂ mechanisms offered by Nature.

In my talk we will (1) discuss the evolution and limitation of naturally existing CO₂ fixing enzymes and pathways. I will (2) present strategies for the engineering and design of artificial CO₂ fixation reactions and pathways (Peter et al. 2015), and (3) outline how these artificial pathways can be realized and further optimized to create synthetic CO₂ fixation modules.

An example for such a synthetic CO₂ fixation module is the CETCH cycle (Schwander et al. 2016). The CETCH cycle is an in vitro-reaction network of 17 enzymes that was established with enzymes originating from nine different organisms of all three domains of life and optimized in several rounds by enzyme engineering and metabolic proofreading. In its version 5.4, the CETCH cycle converts CO₂ into organic molecules at a rate of 5 nanomoles of CO₂ per minute per milligram of protein. This is slightly faster than the Calvin cycle under comparable conditions and notably at 20% less energy per CO₂ fixed.